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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the behavioral bar is lower. The description adds pricing data the annotations cannot convey: ¥0.1 per call, charged only on success, with automatic refund on failure or empty results. That is exactly the kind of cost/retry context an agent needs before calling repeatedly.

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, front-loaded with purpose, then return fields, then use cases, then billing. Each sentence carries distinct information with no repetition of the name or title.

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?

No output schema exists, so the description must describe return values, and it does (nickname, followers, likes, bio, verification). Combined with the billing note and a single required parameter, an agent has everything needed to decide and invoke. Only the absence of an explicit sibling comparison keeps it below the top score.

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%, so both uid and _token are already documented in the schema, including the recommended header-based auth. The description adds no syntax or format guidance for uid beyond what the schema states, so 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?

States a specific verb and resource (获取微博用户信息) and enumerates the returned fields (昵称、粉丝数、获赞数、简介、认证状态), which clearly separates it from siblings like weibo_user_posts or weibo_post_detail. It stops short of naming an alternative sibling explicitly, but the resource boundary is 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?

Gives concrete use cases: influencer screening, account profiling, follower-count tiering. That tells the agent when the tool fits, but it does not state when to use the sibling weibo_user_posts instead, nor any negative case.

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