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

Annotations already declare readOnlyHint=true, covering the safe-read nature. The description adds that pagination uses page_token, but detailed token behavior lives in the schema rather than the description, and no other runtime traits like ordering or first-page behavior are disclosed.

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?

A single, front-loaded sentence with no filler. It states the resource, the key parameter, and pagination support efficiently.

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 low-complexity, read-only list tool with an output schema and fully documented parameters, the description is nearly sufficient. It lacks an explicit pointer to the profile_url sibling, but the user_id-based naming and description make correct invocation clear.

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 description coverage is 100%, including a detailed contract for page_token as an opaque token. The description adds no meaning beyond the schema: it simply says the tool uses user_id and supports page_token pagination.

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 specifies a clear verb and resource: getting a Weibo user's post list by user_id. It also mentions page_token pagination, and the 'by_user_id' naming distinguishes it from the sibling 'by_profile_url' tool.

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 use when a user_id is available, but it does not explicitly contrast this tool with weibo_get_user_posts_by_profile_url or state when not to use it. The selection criterion is clear but largely left to inference from the tool name.

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