get_user_info

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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly indicates a read-style operation ('Get') and describes the return shape, which is useful. However, it does not disclose auth requirements, failure behavior for invalid sec_user_id, rate limits, or whether a valid login is required.

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?

The description is compact and well-structured with a clear summary line, an Args section, and a Returns section. Every sentence contributes useful information, and there is no redundant or filler content.

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 an output schema, the description covers the main operational need: what the tool does and what it returns. It is not fully complete because it omits auth prerequisites and error scenarios, which the sibling check_login_status suggests may be relevant, but the core call contract is adequately specified.

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 input schema only says sec_user_id is a required string, but the description explains that it is the user's security ID and gives a recognizable prefix pattern (MS4wLjABAAAA). This adds significant semantic value beyond the schema, fully covering the only parameter.

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 opens with a specific verb and resource: 'Get Douyin user profile information.' The listed return fields (nickname, avatar, follower count, etc.) make the scope concrete and clearly differentiate it from siblings like get_user_posts, which concern posts rather than profile data.

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 provides no guidance about when to use this tool versus alternatives. It does not mention exclusions, prerequisites like login status, or point to get_user_posts or check_login_status for adjacent use cases. Usage is only implied by the tool's name and one-line summary.

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