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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the description's 'Read-only' line largely restates structured data. It does add one piece of genuine context not in the annotations: the data belongs to the currently signed-in account rather than a specified user. Nothing about auth requirements or failure modes is disclosed.

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, front-loaded with what is returned, followed by the safety signal. No filler, no redundancy beyond the one-word read-only note.

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 parameters, an output schema covering return values, and full annotation coverage, the description tells an agent everything needed to invoke it. The only small gap is that the auth precondition ('signed-in account') is stated only implicitly.

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 implies no target identifiers are needed by scoping it to 'the signed-in account', which matches the empty schema.

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 a specific resource (the signed-in account's profile) and enumerates exactly which fields are returned (name, email, avatar, creation date, plan status), which distinguishes it from siblings like list_plans and billing_status. It lacks an explicit verb, relying on the tool name for the action, but the scope 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 this is the tool for fetching the current user's identity details. No explicit when-to-use or when-not-to-use guidance is given, and the overlap with billing_status (plan status) or list_plans is not addressed.

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