Set Appearance

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds nothing beyond that — it does not say existing appearance assignments are overwritten, nor what happens if the name is not found (that detail lives only in the schema).

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 tight sentence with the verb and scope front-loaded and no filler. It is appropriately sized for a simple setter, though there is no additional structure to earn a 5.

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?

There is no output schema, so the description should ideally say what a successful (or failed) assignment returns. For a straightforward idempotent setter with annotation coverage and a well-documented schema, the description is minimally adequate but leaves the return/confirmation behavior unstated.

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 75%, so the schema already documents the parameters, including the valuable note that appearance_name must match the UI display language. The description contributes no parameter meaning of its own, 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 (assign), resource (material appearance), and valid targets (body, face, component) from a named library. It is clear what the tool does, but it never distinguishes itself from the sibling set_color, which an agent will likely confuse with this.

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?

Usage is implied by the target list, but there is no explicit when-to-use guidance, no statement of when to prefer set_appearance over set_color, and no indication of prerequisites (e.g., the target must exist or be named exactly).

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