Exercise core skill discovery with additional directory layouts

plugins/agent-plugins-conformance-core/README.md

@@ -10,7 +10,7 @@ Node.js 22 or newer must be available as `node` on the client's executable searc
 
 | Case IDs | What the check establishes |
 | --- | --- |
-| `skills.discovery.immediate-children` | The agent reports the expected markers for both immediate child skills loaded through the client. Discovery depends on that account. |
+| `skills.discovery.immediate-children` | The agent reports the expected markers for both valid immediate-child skills loaded through the client; the fixture also includes a README-only directory and a nested reference `SKILL.md`. Discovery depends on that account. |
 | `mcp.stdio.tool-availability.cwd-omitted`, `mcp.stdio.tool-availability.cwd-plugin-relative`, `mcp.stdio.tool-availability.cwd-plugin-root`, `mcp.stdio.tool-availability.cwd-plugin-data` | Each server returned a valid observation. |
 | `mcp.stdio.cwd.omitted` | Omitted `cwd` uses the package root. |
 | `mcp.stdio.cwd.plugin-relative`, `mcp.stdio.cwd.plugin-root` | Relative and root-placeholder `cwd` resolve to `probe-workdir`. |

plugins/agent-plugins-conformance-core/skills/conformance-alpha/references/conformance-nested/SKILL.md

@@ -0,0 +1,8 @@
+---
+name: conformance-nested
+description: A nested reference fixture accompanying the core discovery skills.
+---
+
+# Nested reference fixture
+
+This file is present as a nested reference resource.

plugins/agent-plugins-conformance-core/skills/without-skill/README.md

@@ -0,0 +1 @@
+This directory intentionally contains no skill definition.

test/package.test.mjs

@@ -23,18 +23,23 @@ test('plugin and MCP target the same published specification version', async ()
   assert.equal((await load('mcp')).$schema, 'https://agent-plugins.org/schemas/1.0.0/mcp.schema.json');
 });
 
-test('primary run skill is separate from the two core discovery witnesses', async () => {
+test('primary run skill is separate from the core discovery fixture layout', async () => {
   const primary = new URL('../plugins/agent-plugins-conformance/', import.meta.url);
   const core = new URL('../plugins/agent-plugins-conformance-core/', import.meta.url);
   assert.deepEqual((await readdir(new URL('skills/', primary))).sort(), ['run-conformance']);
-  assert.deepEqual((await readdir(new URL('skills/', core))).sort(), ['conformance-alpha', 'conformance-beta']);
+  const skills = new URL('skills/', core);
+  assert.deepEqual((await readdir(skills)).sort(), ['conformance-alpha', 'conformance-beta', 'without-skill']);
   const runSkill = await readFile(new URL('skills/run-conformance/SKILL.md', primary), 'utf8');
   assert.match(runSkill, /^name: run-conformance$/m);
   for (const name of ['alpha', 'beta']) {
     const witness = await readFile(new URL(`skills/conformance-${name}/SKILL.md`, core), 'utf8');
     assert.match(witness, new RegExp(`^name: conformance-${name}$`, 'm'));
     assert.ok(witness.includes(`APC_${name.toUpperCase()}_V1`));
   }
+  assert.deepEqual((await readdir(new URL('without-skill/', skills))).sort(), ['README.md']);
+  const nested = await readFile(new URL('conformance-alpha/references/conformance-nested/SKILL.md', skills), 'utf8');
+  assert.match(nested, /^name: conformance-nested$/m);
+  assert.match(nested, /^description: .+$/m);
 });
 
 test('recovery fixture contains exactly the intended invalid manifest and MCP fields', async () => {