ctrl_list

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

Annotations already mark it as read-only and non-destructive. The description adds useful behavioral context by stating that it lists all animatable tracks and includes controller type and key count, plus a diagnostic-first recommendation. No side effects or safety contradictions are present.

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?

The description is compact and front-loaded: the primary function appears first, followed by a concrete troubleshooting use case. The bilingual repetition is purposeful for the API's audience and adds no filler.

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 simple read-only list tool, the description covers what the tool returns, why an agent would use it, and when to prioritize it. The input schema covers the parameters, and annotations cover the safety profile, so nothing essential 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 the baseline applies. The description does not add parameter-level detail beyond the schema, but the parameters (limit, offset, objects) are already fully documented in the input schema.

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?

The description uses a specific verb ('List') with a clear resource ('every animatable track of an object') and states the returned information ('controller type and key count'). The diagnostic framing ('why a property will not animate') clearly separates it from sibling animation tools like anim_set_key or ctrl_set_value.

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 explicit guidance on when to use the tool: 'Check it first when wondering why a property will not animate.' It does not explicitly name alternatives or state when not to use it, but the usage context is clear enough for an agent to select it appropriately.

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