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

Annotations already declare non-read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds real context beyond them: this call transitions/locks the character into an approved state that unlocks downstream pose and animation work, and it is explicitly free (implying other operations may not be). It does not say whether approval can be revoked.

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 sentences, front-loaded with the effect, then the cost, then the precondition. The one-word 'Free.' fragment is justified because cost is decision-relevant information an agent cannot get elsewhere.

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 single-parameter state-changing tool with no output schema, the description covers the effect, the precondition, and the cost, which is enough to call it correctly. Remaining gaps are minor: no statement of what failure looks like (e.g., character not ready) or whether approval can be undone.

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?

There is a single parameter (project_id) with 100% schema description coverage, and the schema even states where to obtain it ('from create_mascot or list_mascots'). The description adds nothing about parameters, so it sits at the baseline for this level of schema coverage.

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 action (locks in the current character) and the concrete downstream benefit (poses and animations can be made from it), which implicitly distinguishes it from add_pose and animate_mascot. It stops short of explicitly naming a sibling as an alternative, so it is clear but not maximally differentiating.

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 an explicit gating precondition: 'Only call this after the user has seen the character and accepted it,' which tells the agent when not to call it. It does not name alternatives or describe what to do if the user has not yet accepted, so it falls short of a full when/when-not/alternative routing.

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