diff --git a/alfred/agent/agent.py b/alfred/agent/agent.py
index 31a4252..cfa9ebe 100644
--- a/alfred/agent/agent.py
+++ b/alfred/agent/agent.py
@@ -140,7 +140,7 @@ class Agent:
         memory.save()
         return final_response
 
-    def _execute_tool_call(self, tool_call: dict[str, Any]) -> dict[str, Any]:
+    def _execute_tool_call(self, tool_call: dict[str, Any]) -> dict[str, Any]:  # noqa: PLR0911
         """
         Execute a single tool call.
 
@@ -183,25 +183,86 @@ class Agent:
             }
 
         tool = self.tools[tool_name]
+        memory = get_memory()
+
+        # Cache lookup — for tools flagged cacheable, short-circuit on hit.
+        cache_key_value = self._cache_key_for(tool, args)
+        if cache_key_value is not None:
+            cached = memory.stm.tool_results.get(tool_name, cache_key_value)
+            if cached is not None:
+                logger.info(
+                    f"Tool cache HIT: {tool_name}[{cache_key_value}]"
+                )
+                self._post_tool_side_effects(tool_name, args, cached, from_cache=True)
+                return {**cached, "_from_cache": True}
 
         # Execute tool
         try:
             result = tool.func(**args)
-            return result
         except KeyboardInterrupt:
             # Don't catch KeyboardInterrupt - let it propagate
             raise
         except TypeError as e:
             # Bad arguments
-            memory = get_memory()
             memory.episodic.add_error(tool_name, f"bad_args: {e}")
             return {"error": "bad_args", "message": str(e), "tool": tool_name}
         except Exception as e:
             # Other errors
-            memory = get_memory()
             memory.episodic.add_error(tool_name, str(e))
             return {"error": "execution_failed", "message": str(e), "tool": tool_name}
 
+        # Persist + side effects only on successful results.
+        if isinstance(result, dict) and result.get("status") == "ok":
+            if cache_key_value is not None:
+                memory.stm.tool_results.put(tool_name, cache_key_value, result)
+            self._post_tool_side_effects(tool_name, args, result, from_cache=False)
+            memory.save()
+
+        return result
+
+    @staticmethod
+    def _cache_key_for(tool: Tool, args: dict[str, Any]) -> str | None:
+        """Return the cache key value for this call, or None if not cacheable."""
+        if tool.cache_key is None:
+            return None
+        value = args.get(tool.cache_key)
+        if value is None:
+            return None
+        return str(value)
+
+    def _post_tool_side_effects(
+        self,
+        tool_name: str,
+        args: dict[str, Any],
+        result: dict[str, Any],
+        *,
+        from_cache: bool,
+    ) -> None:
+        """
+        Tool-agnostic side effects applied after a successful run or cache hit.
+
+        Today:
+          - Update release_focus when a path-keyed inspector runs.
+          - Refresh episodic.last_search_results on find_torrent cache hits so
+            get_torrent_by_index keeps pointing at the right list.
+        """
+        memory = get_memory()
+        tool = self.tools.get(tool_name)
+
+        # Release focus: any path-keyed inspector updates current_release_path.
+        if tool is not None and tool.cache_key in {"source_path"}:
+            path = args.get(tool.cache_key)
+            if isinstance(path, str) and path:
+                memory.stm.release_focus.focus(path)
+
+        # Episodic refresh when find_torrent's cache short-circuits the call.
+        if from_cache and tool_name == "find_torrent":
+            torrents = result.get("torrents") or []
+            query = args.get("media_title") or ""
+            memory.episodic.store_search_results(
+                query=query, results=torrents, search_type="torrent"
+            )
+
     async def step_streaming(
         self, user_input: str, completion_id: str, created_ts: int, model: str
     ) -> AsyncGenerator[dict[str, Any]]:
diff --git a/alfred/agent/registry.py b/alfred/agent/registry.py
index e45480b..d36b0ee 100644
--- a/alfred/agent/registry.py
+++ b/alfred/agent/registry.py
@@ -20,6 +20,7 @@ class Tool:
     description: str
     func: Callable[..., dict[str, Any]]
     parameters: dict[str, Any]
+    cache_key: str | None = None  # Parameter name to use as STM cache key.
 
 
 _PY_TYPE_TO_JSON = {
@@ -84,11 +85,14 @@ def _create_tool_from_function(func: Callable, spec: ToolSpec | None = None) ->
         "required": required,
     }
 
+    cache_key = spec.cache.key if spec is not None and spec.cache is not None else None
+
     return Tool(
         name=func.__name__,
         description=description,
         func=func,
         parameters=parameters,
+        cache_key=cache_key,
     )
 
 
diff --git a/alfred/agent/tools/spec.py b/alfred/agent/tools/spec.py
index 8fef324..4c6e9b8 100644
--- a/alfred/agent/tools/spec.py
+++ b/alfred/agent/tools/spec.py
@@ -61,6 +61,18 @@ class ReturnsSpec:
         )
 
 
+@dataclass(frozen=True)
+class CacheSpec:
+    """Marks a tool as cacheable in STM.tool_results, keyed by one of its parameters."""
+
+    key: str  # Name of the parameter whose value is the cache key.
+
+    @classmethod
+    def from_dict(cls, data: dict) -> CacheSpec:
+        _require(data, "key", "cache")
+        return cls(key=str(data["key"]).strip())
+
+
 @dataclass(frozen=True)
 class ToolSpec:
     """Full semantic spec for one tool."""
@@ -73,6 +85,7 @@ class ToolSpec:
     next_steps: str | None
     parameters: dict[str, ParameterSpec]      # name -> ParameterSpec
     returns: dict[str, ReturnsSpec]           # status_key -> ReturnsSpec
+    cache: CacheSpec | None = None            # If present, tool is cached.
 
     @classmethod
     def from_yaml_path(cls, path: Path) -> ToolSpec:
@@ -108,7 +121,12 @@ class ToolSpec:
             for rkey, rdata in returns_raw.items()
         }
 
-        return cls(
+        cache_raw = data.get("cache")
+        if cache_raw is not None and not isinstance(cache_raw, dict):
+            raise ToolSpecError("cache must be a mapping")
+        cache = CacheSpec.from_dict(cache_raw) if cache_raw else None
+
+        spec = cls(
             name=str(data["name"]).strip(),
             summary=str(data["summary"]).strip(),
             description=str(data["description"]).strip(),
@@ -117,7 +135,14 @@ class ToolSpec:
             next_steps=_strip_or_none(data.get("next_steps")),
             parameters=parameters,
             returns=returns,
+            cache=cache,
         )
+        if cache is not None and cache.key not in parameters:
+            raise ToolSpecError(
+                f"cache.key '{cache.key}' is not a declared parameter "
+                f"(declared: {sorted(parameters)})"
+            )
+        return spec
 
     def compile_description(self) -> str:
         """
diff --git a/alfred/agent/tools/specs/analyze_release.yaml b/alfred/agent/tools/specs/analyze_release.yaml
index 352e061..c701fc6 100644
--- a/alfred/agent/tools/specs/analyze_release.yaml
+++ b/alfred/agent/tools/specs/analyze_release.yaml
@@ -37,6 +37,9 @@ next_steps: |
   - media_type in (other, unknown) → ask the user what to do; do not
     auto-route.
 
+cache:
+  key: source_path
+
 parameters:
   release_name:
     description: Raw release folder or file name as it appears on disk.
diff --git a/alfred/agent/tools/specs/find_media_imdb_id.yaml b/alfred/agent/tools/specs/find_media_imdb_id.yaml
index 6d2e207..899f765 100644
--- a/alfred/agent/tools/specs/find_media_imdb_id.yaml
+++ b/alfred/agent/tools/specs/find_media_imdb_id.yaml
@@ -27,6 +27,9 @@ next_steps: |
   - On status=error (not_found): show the error and ask the user for
     a more precise title.
 
+cache:
+  key: media_title
+
 parameters:
   media_title:
     description: Title to search for. Free-form — TMDB does the matching.
diff --git a/alfred/agent/tools/specs/find_torrent.yaml b/alfred/agent/tools/specs/find_torrent.yaml
index a568939..a14cd9c 100644
--- a/alfred/agent/tools/specs/find_torrent.yaml
+++ b/alfred/agent/tools/specs/find_torrent.yaml
@@ -27,6 +27,9 @@ next_steps: |
   - Once chosen: call add_torrent_by_index(N) — that wraps
     get_torrent_by_index + add_torrent_to_qbittorrent.
 
+cache:
+  key: media_title
+
 parameters:
   media_title:
     description: Title to search for on Knaben. Free-form.
diff --git a/alfred/agent/tools/specs/list_folder.yaml b/alfred/agent/tools/specs/list_folder.yaml
index 67600a3..445fcae 100644
--- a/alfred/agent/tools/specs/list_folder.yaml
+++ b/alfred/agent/tools/specs/list_folder.yaml
@@ -29,6 +29,9 @@ next_steps: |
   - After listing a library folder: use the result to disambiguate a
     destination during resolve_*_destination.
 
+cache:
+  key: path
+
 parameters:
   folder_type:
     description: Logical folder key (download, torrent, movie, tv_show, ...).
diff --git a/alfred/agent/tools/specs/probe_media.yaml b/alfred/agent/tools/specs/probe_media.yaml
index a0c7a74..8721d61 100644
--- a/alfred/agent/tools/specs/probe_media.yaml
+++ b/alfred/agent/tools/specs/probe_media.yaml
@@ -27,6 +27,9 @@ next_steps: |
     "this is 7.1 DTS, want to keep it?"); rarely chained directly to
     another tool.
 
+cache:
+  key: source_path
+
 parameters:
   source_path:
     description: Absolute path to the video file to probe.
diff --git a/alfred/infrastructure/persistence/memory/stm/components/__init__.py b/alfred/infrastructure/persistence/memory/stm/components/__init__.py
index 22cddcc..5b0e737 100644
--- a/alfred/infrastructure/persistence/memory/stm/components/__init__.py
+++ b/alfred/infrastructure/persistence/memory/stm/components/__init__.py
@@ -1,5 +1,13 @@
 from .conversation import Conversation
 from .entities import Entities
+from .release_focus import ReleaseFocus
+from .tool_results import ToolResultsCache
 from .workflow import Workflow
 
-__all__ = ["Conversation", "Workflow", "Entities"]
+__all__ = [
+    "Conversation",
+    "Entities",
+    "ReleaseFocus",
+    "ToolResultsCache",
+    "Workflow",
+]
diff --git a/alfred/infrastructure/persistence/memory/stm/components/release_focus.py b/alfred/infrastructure/persistence/memory/stm/components/release_focus.py
new file mode 100644
index 0000000..3a3a4c5
--- /dev/null
+++ b/alfred/infrastructure/persistence/memory/stm/components/release_focus.py
@@ -0,0 +1,68 @@
+"""ReleaseFocus — which release(s) the conversation is currently about.
+
+Two slots:
+  - current_release_path: the single release the user is actively
+    working on. Updated automatically when an inspector tool
+    (analyze_release, probe_media, ...) is called on a path.
+  - working_set: every release path mentioned in this session, in
+    insertion order. Useful to answer "what were we looking at?".
+
+Only paths are stored — full metadata lives in each release's
+`.alfred/metadata.yaml`. Read it via a dedicated tool when needed.
+"""
+
+import logging
+from dataclasses import dataclass, field
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class ReleaseFocus:
+    current_release_path: str | None = None
+    working_set: list[str] = field(default_factory=list)
+
+    def focus(self, path: str) -> None:
+        """Set the current release and add it to the working set."""
+        self.current_release_path = path
+        if path not in self.working_set:
+            self.working_set.append(path)
+            logger.debug(f"ReleaseFocus: added '{path}' to working set")
+        logger.debug(f"ReleaseFocus: current -> '{path}'")
+
+    def clear(self) -> None:
+        self.current_release_path = None
+        self.working_set = []
+
+    @classmethod
+    def describe(cls) -> dict:
+        return {
+            "name": "ReleaseFocus",
+            "tier": "stm",
+            "access": "read",
+            "description": (
+                "Tracks which release the conversation is centred on. "
+                "Updated automatically when an inspector tool runs on a "
+                "release path. Read 'current_release_path' to know what "
+                "the user is talking about without re-asking; read "
+                "'working_set' for the list of releases touched in this "
+                "session."
+            ),
+            "fields": {
+                "current_release_path": (
+                    "Absolute path of the release currently in focus, or "
+                    "None if no release has been inspected yet."
+                ),
+                "working_set": (
+                    "Ordered list of every release path inspected during "
+                    "the session. Refer to entries by their basename when "
+                    "talking to the user."
+                ),
+            },
+        }
+
+    def to_dict(self) -> dict:
+        return {
+            "current_release_path": self.current_release_path,
+            "working_set": list(self.working_set),
+        }
diff --git a/alfred/infrastructure/persistence/memory/stm/components/tool_results.py b/alfred/infrastructure/persistence/memory/stm/components/tool_results.py
new file mode 100644
index 0000000..62eb51f
--- /dev/null
+++ b/alfred/infrastructure/persistence/memory/stm/components/tool_results.py
@@ -0,0 +1,69 @@
+"""ToolResultsCache — per-session cache of read-only tool results.
+
+Tools flagged with `cache.key` in their YAML spec write their results
+here automatically (via Agent._execute_tool_call). Lookup happens
+before execution: a hit returns the cached value without re-calling
+the underlying tool.
+
+Lives for the duration of the session — cleared on memory.clear_session()
+or on a fresh process start.
+"""
+
+import logging
+from dataclasses import dataclass, field
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class ToolResultsCache:
+    # {tool_name: {key: result}}
+    results: dict[str, dict[str, Any]] = field(default_factory=dict)
+
+    def get(self, tool_name: str, key: str) -> dict | None:
+        bucket = self.results.get(tool_name)
+        if bucket is None:
+            return None
+        return bucket.get(key)
+
+    def put(self, tool_name: str, key: str, result: dict) -> None:
+        self.results.setdefault(tool_name, {})[key] = result
+        logger.debug(f"ToolResultsCache: stored {tool_name}[{key}]")
+
+    def keys_for(self, tool_name: str) -> list[str]:
+        return list(self.results.get(tool_name, {}).keys())
+
+    def clear(self) -> None:
+        self.results = {}
+
+    @classmethod
+    def describe(cls) -> dict:
+        return {
+            "name": "ToolResultsCache",
+            "tier": "stm",
+            "access": "read",
+            "description": (
+                "Per-session cache of read-only tool results, keyed by tool "
+                "name and a natural identifier from the tool's arguments "
+                "(usually a path or a title). Hits short-circuit the next "
+                "call to the same tool with the same key. Populated "
+                "automatically by the agent — do not write to it directly. "
+                "Consult it before suggesting a probe / analyze you may "
+                "have already done in this session."
+            ),
+            "fields": {
+                "results": (
+                    "Nested dict: {tool_name: {cache_key: result}}. "
+                    "Read-only inventory; the agent should reference cached "
+                    "values rather than re-calling the tool."
+                ),
+            },
+        }
+
+    def to_dict(self) -> dict:
+        # Surface only the index (tool + keys), not the payloads — payloads
+        # can be large and the prompt only needs to know what's available.
+        return {
+            tool: list(bucket.keys()) for tool, bucket in self.results.items()
+        }
diff --git a/alfred/infrastructure/persistence/memory/stm/stm.py b/alfred/infrastructure/persistence/memory/stm/stm.py
index 5338228..a25bcf2 100644
--- a/alfred/infrastructure/persistence/memory/stm/stm.py
+++ b/alfred/infrastructure/persistence/memory/stm/stm.py
@@ -3,7 +3,13 @@
 import logging
 from dataclasses import dataclass, field
 
-from .components import Conversation, Entities, Workflow
+from .components import (
+    Conversation,
+    Entities,
+    ReleaseFocus,
+    ToolResultsCache,
+    Workflow,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -22,6 +28,8 @@ class ShortTermMemory:
     conversation: Conversation = field(default_factory=Conversation)
     workflow: Workflow = field(default_factory=Workflow)
     entities: Entities = field(default_factory=Entities)
+    tool_results: ToolResultsCache = field(default_factory=ToolResultsCache)
+    release_focus: ReleaseFocus = field(default_factory=ReleaseFocus)
 
     # Convenience proxies kept for backward compatibility with existing callers
     @property
@@ -79,6 +87,8 @@ class ShortTermMemory:
         self.conversation.clear()
         self.workflow.clear()
         self.entities.clear()
+        self.tool_results.clear()
+        self.release_focus.clear()
         logger.info("STM: Cleared")
 
     def to_dict(self) -> dict:
@@ -88,4 +98,6 @@ class ShortTermMemory:
             "extracted_entities": self.entities.data,
             "current_topic": self.entities.topic,
             "language": self.conversation.language,
+            "tool_results": self.tool_results.to_dict(),
+            "release_focus": self.release_focus.to_dict(),
         }