whoami

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral detail beyond them: it discloses the exact fields returned and a conditional branch where the role list appears if no role is selected yet, which is exactly the kind of non-obvious behavior the description should carry.

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 with zero filler. The primary behavior is front-loaded and the conditional case is appended second, which is the correct ordering for an agent scanning text.

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?

There is no output schema, so the description properly carries the return-value burden by naming the fields, and annotations cover the safety semantics. It stops short of describing the shape of the role-list fallback, but for a zero-parameter, read-only introspection tool this is nearly complete.

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 for the description to clarify and the baseline is 4. No parameter text is needed or expected.

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 gives a specific verb ('Shows') and a clearly scoped resource ('my account'), and enumerates the returned fields (UUID, name, role, description), so it is easily distinguished from the sibling list_accounts, which operates on all accounts. It does not explicitly name or contrast against a sibling, which keeps it just below the top score.

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?

Usage is implied rather than stated: the self-scoped wording ('my account') signals this is a self-inspection tool, and the conditional about an unselected role hints at a first-run state. There is no explicit when-to-use guidance or comparison to alternatives such as list_accounts or use_account.

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