whoami

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

With no annotations, the description carries the burden and does disclose two useful traits: the result is scoped to the 'currently authenticated' account (not an arbitrary user) and it exposes a sensitive API key prefix rather than a full key. It does not state read-only-ness explicitly or what happens without valid auth, but 'Show' plus the enumerated read-only fields make the safety profile unambiguous.

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?

A single front-loaded sentence with zero filler, and the parenthetical return-field list is placed where it adds the most value.

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 introspection tool, the description supplies all the caller needs: what is returned and that it is identity-scoped. Only a note on auth failure behavior or sensitivity of the key prefix would add more.

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 document; baseline 4 applies. The description correctly adds no parameter noise.

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 ('Show') and resource ('the currently authenticated Runhooks account') and enumerates what is returned (name, plan, API key prefix). It is immediately distinguishable from siblings like provision_account or rotate_key, which manage rather than disclose identity.

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 only implied: an agent can infer this is the identity/credential-inspection tool. No explicit when-to-use, no prerequisites, and no mention of the related siblings such as rotate_key or get_usage that an agent might confuse it with.

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