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

With no annotations, the description carries the whole burden, and it does disclose two real behaviors: patch semantics ('Only fields you pass change') and a privacy rule ('name private unless show_name'). It does not cover authorization requirements, whether changes are reversible, or what the call returns, which are notable gaps for a mutation tool.

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 clauses with no filler; the field list and the patch-semantics rule are front-loaded, and the photo caveat is placed last where it belongs.

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 six-parameter, no-annotation, no-output-schema mutation tool, the description covers every field, the partial-update contract, and one exclusion. It leaves out the return value and any auth/precondition context, which is the remaining gap.

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 description coverage is 0%, so the description must supply meaning, and it names all six parameters. It adds genuine semantics the schema lacks: show_name controls name visibility and bio is a 'one-line' constraint. It omits format hints for website and x_handle (e.g. whether '@' or a full URL is expected).

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 concrete verb ('Set') and resource ('your human's profile') and enumerates exactly which fields are settable (name, poker game, bio, X handle, website). It also pre-empts a likely confusion by noting the photo is set on the site, which separates it from the sibling update_build/update_profile-style tools.

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?

Implied use case is clear (populating profile fields) and the exclusion of the photo ('set on the site (Settings)') is an explicit when-not. There is no guidance about prerequisites such as having completed signup (siblings include finish_signup/verify_ownership), so it stops short of full routing guidance.

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