pp_get_partner_usage

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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), and the description adds useful behavioral detail: it requires a valid partner key and returns 401 when the server lacks one. This auth requirement and failure mode go beyond the structured annotations, though broader return behavior is not described.

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 tightly written sentences with the primary purpose stated first and the prerequisite second. There is no filler or redundant restatement of structured data.

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-only tool with rich annotations and no output schema, the description provides what an agent needs: what it returns, the key prerequisite, and the failure condition. No critical context is missing.

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 zero parameters, so there are no parameter semantics to document. The baseline for zero-param tools is 4, and the description does not need to compensate for any schema 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 states a specific return payload (rate-limit usage and account info) scoped to the configured API key, which is clear enough for an agent to know what the tool retrieves. It does not explicitly differentiate from any sibling tool, but the resource is distinct enough in context.

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 description gives a prerequisite (requires a valid partner key) and a failure mode (401 without one), which implies the tool should only be called when a partner key is available. However, it does not state when to choose this tool over alternatives or provide broader usage context.

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