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

Annotations already mark the tool read-only, idempotent, and non-destructive. The description adds meaningful behavior beyond those: results include viewerHasLiked/isMine only when authenticated, and the content is predominantly official-generated with zero site-wide comments, which prevents the agent from suggesting a comment section that doesn't exist. This is valuable context the annotations do not convey.

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?

Two tight paragraphs: the first states the operation and returned components; the second contains a single critical data caveat. Each sentence provides distinct information, front-loaded, and there is no filler.

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 one-parameter, read-only, idempotent lookup, the description covers the return scope (body/media/attach/author), auth-dependent fields, the official-content origin, and the empty-comment warning. With no output schema present, the description sufficiently explains what to expect, and nothing essential is missing for correct invocation.

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?

The schema already fully documents the single id parameter (type, required, description '内容 id（cuid）') with 100% coverage. The description only repeats '按 id' and adds no format, semantics, or edge-case information beyond the schema, so the baseline 3 applies.

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 states the exact operation (query by id), the resource (a single item in the content feed), and enumerates its components (body, media, attached card, author). This clearly differentiates it from sibling getters like get_activity, get_product, and get_creator, and from list_posts, which lists rather than fetches a single post.

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?

The description implies the usage context: fetching a single content item by id, with login-dependent fields. It also provides situational guidance via the caveat about official content and empty comments. However, it doesn't explicitly name alternatives or exclusion criteria, such as pointing to list_posts for browsing the feed, so it lacks the explicit routing found in a 5.

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