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

The description reinforces the destructiveHint annotation by explicitly saying 'MUTATES' and adds the useful guarantee that only provided fields change. However, it does not disclose potential side effects such as what happens to the existing access token when issue_access_token is true. The annotation covers the general destructiveness, so this is adequate but not rich.

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?

The description is brief, front-loaded with the critical mutation warning, and contains no filler. Every sentence adds value: mutation intent, partial-update behavior, and the underlying API endpoint.

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?

Given only four parameters, full schema coverage, and no nested objects, the description provides enough context to select and invoke the tool correctly. The missing return-shape information is minor for a mutation tool, and no output schema exists to compensate.

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 input schema already describes all four parameters, so the baseline is 3. The description adds meaningful parameter-related semantics by stating 'Only provided fields change', which clarifies how optional fields behave during the update. This goes slightly beyond what the schema's individual property descriptions express.

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 clearly states the verb ('MUTATES', 'partially updates') and the resource ('a user's profile'), making the tool's purpose unambiguous. The partial-update framing and the explicit PUT endpoint differentiate it from sibling create/get/list tools even without naming them.

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?

The description implies when to use this tool: when the goal is to mutate an existing user's profile rather than create, read, or list users. It does not explicitly name alternatives or state when not to use it, so the guidance is implied rather than stated.

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