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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful context beyond annotations by requiring authentication and clarifying that results are scoped to the current user. No contradiction with annotations.

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 that conveys the auth requirement and the exact resource being listed. There is no redundant wording or 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 zero-parameter read-only list operation, this description is complete: it states authentication needs, user scope, and the resource returned. The annotations cover safety traits, and no output schema is present, but the description makes the expected result unambiguous.

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 tool has zero parameters and schema description coverage is 100%, so there is nothing for the description to add at the parameter level. The baseline for zero-parameter tools applies, and the description's mention of 'current user' provides relevant implicit context.

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+resource: '列出当前用户拉黑的所有用户' (list all users blocked by the current user). This clearly distinguishes it from sibling tools like block_user and unblock_user, which are mutation actions rather than listing operations.

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 specifies the login requirement and makes the intended use clear: retrieve the current user's block list. It does not explicitly name alternatives or exclusions, but there is no obvious sibling that provides the same block-list read capability, so the context is sufficient.

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