fix(tools): stop cancelled calls before execution and discard late results

CHANGELOG.md

@@ -15,6 +15,8 @@
   the five borough cores load and `CCTV_NYC_MAX_SOURCES` changes the cap. The catalog-wide ceiling is
   unchanged; extra cameras share it round-robin with the other packs.
 
+- Cancelled tool calls refuse actions before execution and discard results that settle after cancellation.
+
 - Treat explicitly current, complete empty vessel coverage as a successful update,
   clearing obsolete contacts while retaining stale or incomplete snapshots.
 

docs/CURRENT-STATE.md

@@ -5310,3 +5310,8 @@ datacenters, dams and the Nepal locator retain that shared credit while displaye
 
 Military fragments stitch by source identity. Different mapped parcels merge only
 when their footprints touch or contain one another, never across a seam tolerance gap.
+
+
+### fix(tools): stop cancelled calls before execution and discard late results
+
+Check cancellation before invoking the tool and after it resolves, including nested calls that share the same signal. This does not promise rollback of an action already completed.

src/tools/catalog-cancellation.test.mjs

@@ -0,0 +1,41 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { composeCatalog, defineTool } from './catalog.js';
+test('cancelled catalog calls cannot execute or return late results', async () => {
+  let calls = 0,
+    release,
+    block = false;
+  const action = defineTool({
+    name: 'fixture_action',
+    kind: 'action',
+    title: 'Fixture',
+    description: 'Offline fixture',
+    inputSchema: { type: 'object' },
+    run: async () => {
+      calls++;
+      return block
+        ? new Promise((r) => (release = r))
+        : { summary: 'fixture', data: {} };
+    },
+  });
+  const catalog = composeCatalog({ tools: [action] });
+  const c = new AbortController();
+  c.abort();
+  await assert.rejects(
+    catalog.call('fixture_action', {}, { signal: c.signal }),
+    { name: 'AbortError' },
+  );
+  assert.equal(calls, 0);
+  block = true;
+  const running = new AbortController();
+  const pending = catalog.call(
+    'fixture_action',
+    {},
+    { signal: running.signal },
+  );
+  while (!release) await Promise.resolve();
+  running.abort();
+  release({ summary: 'late', data: {} });
+  await assert.rejects(pending, { name: 'AbortError' });
+  assert.equal(calls, 1);
+});

src/tools/catalog.js

@@ -178,6 +178,7 @@ export function composeCatalog({
     return chain({ tool, args, signal, ...(parent ? { parent } : {}) });
   };
   const execute = async ({ tool, args, signal }) => {
+    signal?.throwIfAborted();
     const problems = validateValue(tool.inputSchema, args);
     if (problems.length)
       throw new ToolError('invalid_arguments', problems.join('; '));
@@ -194,6 +195,7 @@ export function composeCatalog({
     } catch (error) {
       throw fromSourceError(error);
     }
+    signal?.throwIfAborted();
     if (!result || typeof result.summary !== 'string' || !result.data)
       throw new TypeError(`${tool.name} returned no summary or data`);
     if (