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

The readOnlyHint already declares this is a safe read. The description adds real context beyond that: some fields (liked/isMine) appear only when authenticated, and comments are not part of the payload. No output schema exists, so the field description carries weight, but it does not explain missing/invalid ID behavior or pagination of associations.

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?

It is short, front-loaded, and every clause carries information. The telegraphic, semicolon-and-arrow style is efficient but slightly harder to parse than plain prose.

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 single-parameter read tool with annotations covering safety and no output schema, the description covers what is returned, which fields depend on login, what is absent, and which sibling to use instead. Only error/edge-case behavior is left unspecified.

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?

Schema coverage is 100% (id: content id, cuid), so the baseline is 3. The description adds one useful semantic constraint - the id must be a post ID, not a moment ID - but supplies no format details beyond the schema.

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 description names the specific resource returned (post body, images, associations, plus liked/isMine for logged-in users) and explicitly separates it from the sibling get_moment. It lacks an explicit verb like 'fetch', but the resource and its scope are unambiguous.

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 explicit routing: use get_moment for moment IDs, never mix the two; follow list_posts -> detail -> related activity/product; use comment_moment for moment replies. It also warns not to assume comments exist. Both when-to-use and when-not-to-use are stated.

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