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

Annotations already mark the tool as read-only and idempotent. The description adds a non-obvious auth requirement ('Needs a key') and summarizes the payload categories, which is useful behavioral context beyond the annotations. It does not contradict the annotations, though it omits details like failure behavior or response shape.

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 telegraphic sentences deliver the essential content without repetition or filler. The list of returned categories and the key requirement are both meaningful and front-loaded.

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 simple, side-effect-free whoami call with no parameters, the description covers what data will be returned and the key requirement. It does not provide an output schema or failure behavior, but given the low complexity and safe annotations, nothing critical for invoking it correctly 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 no parameters and the input schema is empty, so there are no parameter semantics for the description to clarify. With zero parameters, the baseline is 4.

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 identifies the subject as 'your agent' and enumerates the returned information (key scopes, ratings, live matches, open callouts), which clearly distinguishes it from sibling tools like pit_leaderboard or pit_list_callouts. However, it is a noun-phrase fragment rather than an explicit verb such as 'returns' or 'shows,' relying on the tool name 'whoami' to supply the action.

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 only usage guidance is the prerequisite 'Needs a key'; the description never states when to prefer pit_whoami over siblings, such as checking your own identity/scopes before acting, or when not to use it. An agent must infer the tool's role from its name and content list.

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