whoami

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

With readOnlyHint already declaring this a safe read, the description adds genuinely useful behavioral context: the identity comes from server configuration rather than the API key, and the response includes permission scope plus the current week's logged time. It stops short of describing response structure, but the output schema covers that.

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 sentences that are mostly front-loaded, but the phrasing is indirect and literary ('Who this server declares time for'), and the second sentence is a long clause chain. The point could be made in fewer, plainer words.

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?

Given an output schema and readOnly/openWorld annotations, the description supplies the missing context an agent needs — that identity is configured rather than derived from the key — and tells the agent to call it first. It is essentially complete for a no-parameter identity probe.

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 the baseline is 4; there is nothing for the description to clarify and no schema gap to compensate for.

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 names what the tool surfaces — the acting identity, its permissions, and time logged this week — which is enough to distinguish it from the CRUD siblings. However, it lacks a clean verb and relies on roundabout phrasing ('Who this server declares time for'), so the purpose is clear but not crisp.

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?

It explicitly instructs 'Call it first' and explains why: Gryzzly API keys belong to a team, not a person, so the identity must be named via configuration. That is an unambiguous when-to-use directive with rationale, which is exactly what usage guidance should do.

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