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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the bar is lower. The description adds genuinely new context — that the profile is public and that bio is capped at 280 characters — but says nothing about partial-update semantics (e.g., whether omitting displayName clears it) or validation failures.

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 names the fields and the one hard constraint; nothing is wasted or buried.

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?

No output schema exists, so the description carries return-value burden, which it ignores. It also omits what the response confirms and how partial updates behave, leaving meaningful gaps for a mutation tool.

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 only 33%: accessToken is documented, but displayName and bio have no schema descriptions. The description compensates for bio with the 280-character limit and hints at both fields, but leaves displayName's constraints (uniqueness, length) unstated.

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 verb ('Change') and precise resource fields ('public display name and/or bio'), which reads clearly as a self-profile edit. It does not explicitly distinguish itself from adjacent siblings like set_status or set_avatar, so it falls short of a full 5.

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?

There is no statement of when to use this versus set_status, set_avatar, or join_request, and no prerequisites beyond the schema. The intended usage is inferable only from the name and the word 'public'.

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