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

Annotations already declare the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the description need not restate it. It does add useful behavior: that avatarFocus/avatarZoom act as crop controls rather than raw coordinates. However, it never says whether unspecified fields are preserved (partial update) or cleared, which is the key behavioral question for a 0-required-param mutation.

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 sentences, zero filler. The primary field list is front-loaded and the avatar crop detail follows as a subordinate clause, which mirrors the nesting in the schema.

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 mutation tool whose annotations already cover reversibility and idempotency, with no output schema to explain, this is nearly complete on parameters and purpose. The remaining gap is partial-update semantics and auth/permission requirements.

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 carry the load, and it does cover all six parameters by name plus the nested avatarFocus x/y. It also supplies meaning the schema lacks: 'avatar URL' (type hint) and the semantics of the ranges (0–100 percent focus, 1–3 zoom) as crop values.

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 ('Change') plus the exact resource fields it mutates (name, bio, avatar URL, location), and extends to the avatar crop sub-fields. It is unambiguous what the tool does, though it makes no attempt to differentiate from siblings (set_theme, update_tile) since those operate on different resources anyway.

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 when-to-use or when-not-to-use guidance, no statement that this edits the caller's own profile, and no prerequisites (e.g. authentication or avatar upload requirements). Usage is only inferable from the verb 'Change'.

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