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

Annotations only cover the safety profile (not read-only, not destructive, not idempotent, closed-world). The description adds the details an agent actually needs to decide: 10-credit cost, 2-4 minute latency, credit refund on failure, and an async job_id return handle. That is genuine behavioral disclosure layered on top of the annotation hints.

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?

Front-loaded with the capability, then cost/latency/return, then failure behavior. Three tight clauses, no repetition of the title, and every sentence carries decision-relevant information.

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 correctly supplies the return contract (job_id for get_animation) plus cost, latency and failure semantics. For a 3-parameter async animation job tool, nothing an agent needs in order to call it and handle the result is missing.

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 100%, so all three parameters are already documented in the schema, including the action's 'beginning, middle and end, in place' constraint and the still_id default. The description adds no format or constraint detail beyond that, 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 and resource with precise scope: a 5-second seamless loop of the approved mascot performing an action on a transparent background. It also names the downstream sibling (get_animation) that consumes the returned job_id, so the agent can place it in the workflow without opening a schema.

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?

The description gives useful operational context (cost, duration, failure handling) and points to get_animation as the follow-up, implying this is the execution step of an animate workflow. However, it never says when to use this versus suggest_animations (for generating action ideas) or add_pose, so alternative selection is left to inference.

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