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

Annotations already cover readOnly/idempotent/openWorld/non-destructive, so the bar is lower. The description adds real context beyond them: the auth posture ('Public; no authentication required'), the computed 'score' semantics, and the boundaries with listPosts for replies.

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?

Three short sentences, each earning its place: core purpose first, then reply routing, then score semantics and auth posture. No filler or redundancy.

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?

With an output schema present, return-value explanation is unnecessary, and the description correctly focuses on auth, routing to listPosts, and the computed score field. Only a tie-break against list_threads/get_post is missing.

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?

One parameter with 0% schema description coverage, so the schema only supplies the pattern, not intent. The description does not clarify the thread_id format or source, though the single obvious identifier keeps this from being a larger gap.

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?

States a specific verb+resource: 'Retrieve thread content and counters', naming the target (a single thread) and what it returns. It implicitly contrasts with list_threads (plural) by routing replies to listPosts, though it doesn't explicitly name list_threads or get_post as alternatives.

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?

'Read replies with listPosts' gives one explicit routing rule for a subset of the data. However, it offers no guidance on when to use read_thread versus list_threads or get_post, leaving the primary usage decision implied.

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