katto_list_clip_lengths

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

The description adds context beyond the annotations by explicitly stating 'Read-only' and the immutability note. This aligns with the readOnlyHint and idempotentHint annotations, providing the agent with a clear behavioral model without any contradictions.

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 two sentences long, focused, and free of redundant information. It delivers the key facts (read-only, valid values, immutability) without any fluff, making it easy to parse and act upon.

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 simple nature (no parameters, no output schema), the description fully covers what an agent needs to know: what it lists, why it matters, and a critical constraint. No additional details are necessary for correct usage.

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?

This tool has zero parameters, so there is no parameter information to convey. The description's mention of config.clipLength refers to the create tool's parameter, which provides useful context without adding confusion about this tool's own parameters.

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 clearly states the tool's purpose: listing valid values for the optional config.clipLength field used in katto_create_clip_job. It also notes the read-only nature and the field's immutability after creation, making it unambiguous what this tool does.

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 explicitly says 'Read-only' and explains that clipLength is fixed at creation and cannot be changed by re-render, which guides the agent on when to use this tool (before creation) and when not to use it (during rerender). The context of sibling tools (create, rerender) reinforces this guidance.

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