list_friends

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

The annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safe read-only nature is covered outside the description. The description only adds the explicit HTTP method and path; it does not disclose response behavior, auth requirements, or other operational traits.

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?

The description is very short and puts the core operation first, with the endpoint clearly separated. It loses a point because the opening 'Get Friends' largely restates the tool name and adds little beyond the endpoint.

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 parameterless, read-only endpoint with an output schema and safety annotations, the description is minimally sufficient. However, it gives no context about what 'friends' means, what the response contains, or when this is the appropriate endpoint among many sibling list tools.

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 the input schema is empty, so there is no parameter information the description needs to compensate for. It provides no parameter semantics, but none are required.

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 states a concrete verb and resource ('Get Friends') and provides the HTTP endpoint 'GET /friends', making the basic purpose clear. It does not differentiate list_friends from sibling list tools such as list_users or list_accounts, which keeps it from a 5.

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 rather than the many sibling list/get tools, no mention of prerequisites, and no exclusions or alternative tool names. The description simply restates what the endpoint does.

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