list_contacts

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds nothing further — no pagination behavior (limit cap of 200), no result shape, no auth context — which leaves the behavioral burden unmet.

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?

It is a single short, front-loaded sentence with zero wasted words. But it is terse to the point of under-specification rather than effectively concise, so it earns only a middling score.

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 3-parameter tool with no output schema and 0% schema documentation, the description should explain the filter parameters, the list semantics and the return behavior. It supplies none of this, leaving the definition too thin for an agent to call it correctly.

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 description coverage is 0%, so all three parameters (limit, keyword, username) are undocumented anywhere. The description does not mention any of them, nor explain that keyword/username are optional filters or that limit caps at 200, so it fails to compensate for the coverage gap.

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 (查询微信联系人信息), so the agent knows it deals with WeChat contacts. However it is vague about scope — it doesn't say whether it lists all contacts or searches/filters them, and it offers no differentiation from the many sibling list_/search_ tools in the catalog.

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?

There is no guidance on when to use this tool versus alternatives such as list_session_senders or search_messages, nor any prerequisites (e.g. auth/export requirement). Usage must be entirely inferred from the name.

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