wechat_get_contacts

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

With no annotations, the description carries the full behavioral burden, yet it discloses nothing about pagination, rate limits, auth requirements, or ordering. It adds the category list, but that information is already in the schema, so no genuine behavioral context is contributed.

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 with no filler or redundancy. It is appropriately sized, though it stops short of earning a 5 because the sentence spends its words re-listing categories already present in the schema rather than adding new guidance.

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?

An output schema exists, so return values need not be described, and the schema covers all three parameters. However, with no annotations and no usage guidance, the definition leaves the read-only nature, pagination behavior of limit, and the group-contacts overlap with siblings unaddressed.

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 100%, so the schema already documents kind, limit, and detail thoroughly. The description's category enumeration merely restates the kind values (friends/groups/公众号/服务号/企业微信) without adding format, default, or interaction semantics. Baseline 3 applies when the schema does the heavy lifting.

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 (获取) and resource (通讯录) and enumerates the contact categories, so the agent knows exactly what data comes back. It is clear enough to distinguish from send_* siblings, but it never addresses the overlapping wechat_get_group_members sibling, leaving boundary ambiguity for the group-contact case.

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 indication of when to use this tool versus alternatives. Given that wechat_get_group_members also returns group-related contacts and wechat_get_recent_sessions covers chats, the definition should have stated the routing condition but does not.

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