katto_list_caption_styles

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

Annotations already declare readOnlyHint and idempotentHint, and the description adds useful behavioral context: the response contains id + label pairs, and the values are valid presets for a specific downstream tool. The example further clarifies what kind of data to expect. No side effects or hidden behaviors are omitted.

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, front-loaded sentences with no filler. The read-only declaration leads, then the purpose, then the usage guidance. Every sentence adds value; even the read-only reminder is harmless reinforcement.

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 zero-parameter, read-only, no-output-schema tool, the description is complete. It tells the agent what the tool returns, why it matters, when to call it, and gives a concrete example. An agent can invoke it correctly without needing additional information.

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?

The tool has zero parameters and 100% schema description coverage, so the base score is 4. The description does not need to explain inputs. It instead clarifies what the returned values represent, which is sufficient.

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: lists the valid caption_style preset names for katto_rerender_clip. The example 'hormozi' and mention of id + label make the purpose concrete. It is clearly distinct from sibling tools like katto_list_sources or katto_list_clip_lengths.

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?

Explicitly instructs the agent to call this before re-rendering so it passes a real preset instead of guessing. This gives clear timing and rationale, though it does not enumerate alternative tools or when not to use this tool. The dependency on katto_rerender_clip provides adequate context.

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