Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With annotations covering safety and open-world traits, the description still adds substantial non-obvious behavior: shared HTTP submission quotas, success meaning 'pending review, not published', and a non-idempotency consequence stated operationally ('do not retry a successful submission'). The privacy admonition (no secrets, private prompts, or user data) further constrains how to compose the payload.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Five short sentences, each carrying a distinct constraint — classification, authorization, privacy, quota/lifecycle, retry. Front-loaded with the most decision-relevant framing ('Optional external write'). No filler, though the privacy sentence packs three rules into one clause stack.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter write tool with no output schema, the description supplies the full decision envelope: whether to call at all, what success looks like, how test entries behave, and the retry prohibition. Remaining gaps (per-field content guidance for agent_name/model_name) are minor relative to what is covered.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

At 29% schema coverage the description needs to compensate, and it partially does: 'mark tests with is_test=true' reinforces the one documented boolean, and 'describe discovery honestly' gives intent for the discovery_notes/discovery_route pair. However, agent_name, model_name, message content expectations, and the enum options for discovery_route remain undocumented in both places.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The opening clause 'Optional external write: submit a message to a private review queue for possible public publication' names a specific verb (submit), resource (message/guestbook), and the exact lifecycle outcome (queued, not published). This implicitly separates it from the read-only sibling list_guestbook_messages, though that sibling is never named.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear gating condition — 'Use only when authorized by your actual task and client permissions' — plus a post-call rule ('Do not retry a successful submission'). What's missing is explicit routing against alternatives (e.g., use list_guestbook_messages to read instead), which would be needed for a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.