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

Annotations already cover the safety profile (readOnly, non-destructive, open-world), and the description adds real behavioral context beyond them: the profile is public-only, results are capped at the 3 most recent posts, and the response additionally reports follow status when the caller is logged in. It doesn't mention error behavior for nonexistent users or auth requirements, but with annotations carrying the safety signal this is solid.

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?

Four short sentences, front-loaded with the resource and its return fields before moving to input format and edge behavior. There is no filler, though the closing usage examples are slightly redundant with the opening statement of purpose.

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 no output schema available, the description compensates by enumerating exactly what comes back (profile fields, counts, 3 recent posts, viewer follow state) and how the identifier may be formatted. For a single-parameter read tool, nothing an agent needs in order to call it correctly 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?

Schema coverage is 100% and the parameter's own description already states that it accepts a UUID or a username such as @dongtao. The description restates the same facts (ID or username, optional @) without adding format rules, resolution precedence, or error cases, so it adds little beyond the schema. 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 names a specific verb and resource ("查看任意 PowPow 用户的公开主页" – view any user's public profile) and then enumerates the returned fields: nickname, bio, badge count, post/following/follower counts, and the latest 3 posts. This differentiates it from siblings like get_my_account, whoami, and search_users without ambiguity.

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 supplies concrete trigger scenarios in the user's own words ("看看这个人的主页", "@xxx 是谁"), which tells an agent when this is the right call. It stops short of naming an alternative such as search_users or whoami or stating exclusions, so it is clear context without explicit routing.

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