friend_list

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

No annotations are supplied, so the description carries the full behavioral burden. It does usefully disclose the shape of each returned record (uin / name / relationship / tone / notes), which compensates for the missing output schema, but says nothing about result size, pagination, ordering, or auth requirements for a zero-arg tool.

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?

Two tight sentences: the purpose and its scope qualifier come first, then the return payload. Nothing is redundant and every clause carries information.

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 tool with no output schema, the description covers what the tool does and what comes back, which is most of what an agent needs. It stops short of stating whether the whole roster is always returned or whether the caller must handle large lists.

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 takes no parameters and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies; the enumerated return fields are a bonus rather than a parameter explanation.

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 ('查看好友名册') plus a distinguishing scope detail — whether each friend has written a definition or not. That separates it from a pure friend-note writer like friend_note, though the description never names a sibling explicitly.

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 read-only listing intent is implied by '查看' and by the fact it returns a roster, but there is no explicit statement of when to call this instead of friend_note or the qzone_* tools. The agent must infer that this is the lookup step before writing notes.

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