Whoami Tool

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

With readOnlyHint=true already covering the safety profile, the description adds real value by enumerating what the call actually returns — identity fields, focus, and work-day start — which is otherwise undocumented since there is no output schema. It doesn't cover edge cases like an invalid or expired token, which keeps it short of a 5.

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 that leads with the subject (who is connected) and then enumerates the returned fields. No filler, no repetition of the tool name beyond what's needed to anchor meaning.

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 read tool with no output schema and only a readOnlyHint annotation, the description carries the right load by describing the returned payload. Minor gap: it doesn't clarify the format or scope of 'focused on' or 'work day started', which an agent may need to interpret the response.

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 disambiguate; the baseline of 4 applies. The description correctly implies a no-argument call that reports on the caller.

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 the resource precisely — the token owner's identity (name, email, role, timezone) plus their current focus and work-day start — which makes it clearly distinct from siblings like my_day or last_update. The verb is implicit ("Who is connected") rather than an explicit 'returns/identifies', but the intent is unambiguous.

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 it should be called to learn the current authenticated identity and focus state. There is no explicit when-to-use or when-not-to-use guidance, and no mention of how it differs from adjacent tools such as my_day which also surfaces day-level information.

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