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

Annotations already indicate non-read-only and destructive hint, but the description adds behavioral context: references fill durable slots, traits are never inferred, and the avatar is reusable. This goes beyond annotations, though it doesn't elaborate on the destructive nature.

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, front-loaded with the main purpose, no redundant info. Each sentence adds key information (inputs, slot concept, trait handling).

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?

Given the tool's complexity (nested objects, 5 params) and no output schema, the description omits return value and potential side-effect details like what happens on name collision. The core concept is well covered, but agent would benefit from knowing what is returned.

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 high (80%), and the description clarifies semantic aspects not in the schema: references are ordered, slots are durable, and trait parameters (build, age, height) are never inferred. This adds meaning beyond the raw schema definitions.

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?

Clearly states the tool creates a reusable avatar/model from specific input types (generated views, workspace files, URLs). Uses a specific verb ('create') and resource ('avatar/model'), distinguishing it from sibling tools like generate_avatar.

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?

Describes the input composition (ordered references, optional traits) but provides no explicit when-to-use vs alternatives or exclusions. Contexts like 'generate_avatar' exist as siblings but the description doesn't differentiate when this tool should be chosen instead.

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