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

Annotations already declare mutation, destructiveness and world-openness, so the bar is lower; the description still adds real value by stating the auth scope (`users:write`), the mutability scope ('today the request body has a single field'), and the return type. It does not say whether the change is reversible or what happens to unmentioned profile fields, which keeps it from 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?

Three short sentences, each carrying distinct information — action, current payload shape, return value and scope — with the action front-loaded and zero filler.

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 three-parameter mutation with full schema coverage and no output schema, the description covers the essentials and even names the returned DTO. Minor gaps (reversibility, whether partial profile data is affected) remain, but nothing an agent needs to call it correctly is missing.

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%, so the schema already documents `fullName`, `account` and `workspace` in detail. The description's 'pass the new display name' merely restates the schema's own phrasing and adds nothing about the multi-account or workspace override parameters, so the baseline 3 applies.

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 and resource ('Update the current user's profile') and immediately narrows the scope ('request body has a single field (`fullName`)'). It is trivially distinguishable from the read-only sibling pm_get_current_user, so an agent needs no further inference.

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?

Gives clear operating instructions for the call: pass the new display name, note that only one field exists today, and the required API-key scope (`users:write`). It does not explicitly name an alternative or a when-not-to-use condition, so it falls short of a 5.

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