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

Annotations already flag a non-read-only, destructive, non-open-world mutation, and the description adds real value on top: changes propagate site-wide immediately, and passing an empty bio string actively wipes existing content. That clarifies what 'destructive' concretely means here. It stops short of stating reversibility (whether the prior nickname/bio can be recovered) or any auth prerequisite.

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 dense sentences, front-loaded with the action, then constraints, then the propagation fact, then the avatar exclusion. No sentence is filler; every clause conveys an operational detail.

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 two-parameter mutation with full schema coverage and no output schema, the description covers limits, the minimum-one rule, side effects, and the out-of-scope case. It does not say what a success response looks like or whether partial application is possible, which are minor omissions at this complexity.

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 both fields and their length limits, making 3 the baseline. The description does add one genuinely new constraint not encoded in the schema — that at least one of the two fields must be provided (required is empty in the schema) — plus the site-wide effect of the write. That added meaning is modest given the schema already carries lengths and the clear-bio semantics.

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 ('修改用户自己的 PowPow 昵称或个人简介') and scopes it to the caller's own profile, which separates it from read-side siblings like get_user_profile and get_my_account. It also explicitly carves out avatar changes as out of scope, so an agent can route that need elsewhere without opening any schema.

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 concrete usage constraints: at least one field must be supplied, both can be changed together, and an empty-string bio means clear. It also supplies an explicit exclusion (avatar must be changed in the site's own settings). What it lacks is a named sibling alternative for adjacent needs, but the practical routing guidance is present.

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