get_users_by_id_friends

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful context about the special 'me' value for the id parameter and that extended controls response detail, but does not disclose pagination or return structure. 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?

Terse and front-loaded with the endpoint line, followed by parameter explanations. Efficient with no wasted words, though the brevity borders on under-specification.

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?

With an output schema present, the return structure is covered. The description covers the endpoint and both parameters at a basic level. However, it omits what 'friends' means in this domain (contrasting with followers/following) and any pagination behavior, which are relevant for an agent deciding whether this is the right call.

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 the description carries the burden. It does explain id ('slug that identifies the user, or me') and extended ('Extended information to include in the response'), which is some added value. However, 'Extended information' is vague—it does not say what extended information means or how to request it, leaving the string|null parameter semantics unclear.

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 clear verb and resource ('Get friends') and documents the endpoint GET /users/{id}/friends. It is distinguishable from siblings by the explicit 'friends' resource, though it does not explicitly contrast with the closely related followers/following tools.

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?

Provides no guidance on when to use this tool versus alternatives. With siblings like get_users_by_id_followers and get_users_by_id_following present, the description fails to clarify what distinguishes 'friends' from 'followers' or 'following', leaving the agent to infer the difference.

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