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

Annotations already declare readOnlyHint, idempotentHint and closed-world behavior, so the safety profile is covered. The description adds real context beyond that: both accepted auth channels (Bearer header or token argument) and the shape of the payload, including that the mail field may be absent if email is not configured.

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 tight sentences with the core purpose front-loaded and auth/return details trailing. The clause about mail being conditional is slightly tangled but earns its place.

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?

With no output schema, the description does the right thing by sketching the returned profile fields, and it covers the auth requirement. Minor gaps remain around error behavior for missing/invalid tokens, but the tool is simple enough that this is nearly sufficient.

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?

Schema coverage is 100% for the single token parameter, so the schema already documents it. The description only restates the token argument as an alternative to the Authorization header, which is the baseline level of added value.

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 states a specific resource — the profile of the signed-in agent — which is unambiguous and distinct from siblings like search_agents or list_contacts. It does not explicitly name a sibling to distinguish itself from, but no sibling overlaps enough to warrant that.

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 (fetch your own identity, with auth via header or the token argument), but there is no explicit when-to-use or when-not-to-use guidance, and no alternative named for cases like looking up other agents.

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