fix(skills): guard against skills prompt bloat

src/agents/skills.buildworkspaceskillsnapshot.e2e.test.ts

@@ -67,4 +67,170 @@ describe("buildWorkspaceSkillSnapshot", () => {
       "visible-skill",
     ]);
   });
+
+  it("truncates the skills prompt when it exceeds the configured char budget", async () => {
+    const workspaceDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-"));
+
+    // Make a bunch of skills with very long descriptions.
+    for (let i = 0; i < 25; i += 1) {
+      const name = `skill-${String(i).padStart(2, "0")}`;
+      await _writeSkill({
+        dir: path.join(workspaceDir, "skills", name),
+        name,
+        description: "x".repeat(5000),
+      });
+    }
+
+    const snapshot = buildWorkspaceSkillSnapshot(workspaceDir, {
+      config: {
+        skills: {
+          limits: {
+            maxSkillsInPrompt: 100,
+            maxSkillsPromptChars: 1500,
+          },
+        },
+      },
+      managedSkillsDir: path.join(workspaceDir, ".managed"),
+      bundledSkillsDir: path.join(workspaceDir, ".bundled"),
+    });
+
+    expect(snapshot.prompt).toContain("⚠️ Skills truncated");
+    expect(snapshot.prompt.length).toBeLessThan(5000);
+  });
+
+  it("limits discovery for nested repo-style skills roots (dir/skills/*)", async () => {
+    const workspaceDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-"));
+    const repoDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-skills-repo-"));
+
+    for (let i = 0; i < 20; i += 1) {
+      const name = `repo-skill-${String(i).padStart(2, "0")}`;
+      await _writeSkill({
+        dir: path.join(repoDir, "skills", name),
+        name,
+        description: `Desc ${i}`,
+      });
+    }
+
+    const snapshot = buildWorkspaceSkillSnapshot(workspaceDir, {
+      config: {
+        skills: {
+          load: {
+            extraDirs: [repoDir],
+          },
+          limits: {
+            maxCandidatesPerRoot: 5,
+            maxSkillsLoadedPerSource: 5,
+          },
+        },
+      },
+      managedSkillsDir: path.join(workspaceDir, ".managed"),
+      bundledSkillsDir: path.join(workspaceDir, ".bundled"),
+    });
+
+    // We should only have loaded a small subset.
+    expect(snapshot.skills.length).toBeLessThanOrEqual(5);
+    expect(snapshot.prompt).toContain("repo-skill-00");
+    expect(snapshot.prompt).not.toContain("repo-skill-19");
+  });
+
+  it("skips skills whose SKILL.md exceeds maxSkillFileBytes", async () => {
+    const workspaceDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-"));
+
+    await _writeSkill({
+      dir: path.join(workspaceDir, "skills", "small-skill"),
+      name: "small-skill",
+      description: "Small",
+    });
+
+    await _writeSkill({
+      dir: path.join(workspaceDir, "skills", "big-skill"),
+      name: "big-skill",
+      description: "Big",
+      body: "x".repeat(50_000),
+    });
+
+    const snapshot = buildWorkspaceSkillSnapshot(workspaceDir, {
+      config: {
+        skills: {
+          limits: {
+            maxSkillFileBytes: 1000,
+          },
+        },
+      },
+      managedSkillsDir: path.join(workspaceDir, ".managed"),
+      bundledSkillsDir: path.join(workspaceDir, ".bundled"),
+    });
+
+    expect(snapshot.skills.map((s) => s.name)).toContain("small-skill");
+    expect(snapshot.skills.map((s) => s.name)).not.toContain("big-skill");
+    expect(snapshot.prompt).toContain("small-skill");
+    expect(snapshot.prompt).not.toContain("big-skill");
+  });
+
+  it("detects nested skills roots beyond the first 25 entries", async () => {
+    const workspaceDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-"));
+    const repoDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-skills-repo-"));
+
+    // Create 30 nested dirs, but only the last one is an actual skill.
+    for (let i = 0; i < 30; i += 1) {
+      await fs.mkdir(path.join(repoDir, "skills", `entry-${String(i).padStart(2, "0")}`), {
+        recursive: true,
+      });
+    }
+
+    await _writeSkill({
+      dir: path.join(repoDir, "skills", "entry-29"),
+      name: "late-skill",
+      description: "Nested skill discovered late",
+    });
+
+    const snapshot = buildWorkspaceSkillSnapshot(workspaceDir, {
+      config: {
+        skills: {
+          load: {
+            extraDirs: [repoDir],
+          },
+          limits: {
+            maxCandidatesPerRoot: 30,
+            maxSkillsLoadedPerSource: 30,
+          },
+        },
+      },
+      managedSkillsDir: path.join(workspaceDir, ".managed"),
+      bundledSkillsDir: path.join(workspaceDir, ".bundled"),
+    });
+
+    expect(snapshot.skills.map((s) => s.name)).toContain("late-skill");
+    expect(snapshot.prompt).toContain("late-skill");
+  });
+
+  it("enforces maxSkillFileBytes for root-level SKILL.md", async () => {
+    const workspaceDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-"));
+    const rootSkillDir = await fs.mkdtemp(path.join(os.tmpdir(), "openclaw-root-skill-"));
+
+    await _writeSkill({
+      dir: rootSkillDir,
+      name: "root-big-skill",
+      description: "Big",
+      body: "x".repeat(50_000),
+    });
+
+    const snapshot = buildWorkspaceSkillSnapshot(workspaceDir, {
+      config: {
+        skills: {
+          load: {
+            extraDirs: [rootSkillDir],
+          },
+          limits: {
+            maxSkillFileBytes: 1000,
+          },
+        },
+      },
+      managedSkillsDir: path.join(workspaceDir, ".managed"),
+      bundledSkillsDir: path.join(workspaceDir, ".bundled"),
+    });
+
+    expect(snapshot.skills.map((s) => s.name)).not.toContain("root-big-skill");
+    expect(snapshot.prompt).not.toContain("root-big-skill");
+  });
 });