cursor_whoami

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

No annotations are provided, so the description carries the burden; it discloses the observable effect (key validation result and the bound identity) and implies a harmless read-only call. It does not explicitly state there are no side effects, no rate-limit behavior, or the exact response shape, which keeps it out of the top score.

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 short sentences, zero filler, with the primary purpose front-loaded ahead of the recovery guidance. Every clause earns its place.

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-param, no-output-schema identity check, the description covers what it does and when to reach for it. It could add a note that it is side-effect-free and requires no arguments, but nothing essential is missing for correct invocation.

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 is nothing to disambiguate; baseline for a no-arg tool applies. The description correctly does not invent parameters.

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 ('verify') plus two concrete resources ('API key', 'identity'), which is distinct from every sibling (launch/status/followup/result/cancel/list/models/usage). An agent can tell exactly what this tool returns without opening a schema.

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?

Gives an explicit trigger condition: call this first when other tools fail with auth errors. That is actionable routing guidance. It stops short of naming which error classes qualify or an alternative diagnostic, so it is clear context without full when-not coverage.

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