Who am I

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so 'Read-only' in the description is a restatement rather than added value. It does add the scope of the returned identity (account/workspace API key, workspaces, plans), which is useful context, but it omits any note on auth requirements or throttling. With rich annotations covering the safety profile, this is adequate but thin.

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, safety attribute front-loaded, then the substance of what is returned. No filler, nothing an agent has to read twice.

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 diagnostic with no output schema, the description is the only place to learn what comes back, and it names it precisely: the account or workspace API key in use, plus its workspaces and plans. Nothing needed to call 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 zero parameters, so the baseline is 4. The description correctly adds nothing about argument syntax because there is none, and it does not mislead about inputs.

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 and resource: it 'shows which Check'd account or workspace API key this server uses, its workspaces and plans.' That is well beyond restating the name 'whoami' and it clearly distinguishes this tool from the list_*/get_* siblings, which enumerate issues, runs, and findings rather than identity/credential scope.

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?

There is no explicit when-to-use statement, no prerequisites, and no named alternatives. The 'whoami' convention makes the purpose inferable and there is no competing tool that overlaps, but the description leaves the agent to infer that this is the right call for verifying which key/account is active. Usage is implied, not stated.

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