katto_rerender_clip

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

The description goes well beyond annotations by explicitly disclosing that the call is free and does not consume video quota, that it starts a new render and is not idempotent, and that the original clip is preserved. It also explains the return value and the required follow-up polling step.

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, with every sentence contributing distinct information: what the tool does, its cost characteristics, its behavioral guarantees, and the expected result/next step. There is no repetition of schema details or annotations.

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 moderate-complexity tool with no output schema, the description provides enough information to invoke the tool correctly and understand the outcome: it returns a rerender_id and the caller must poll katto_get_rerender. Combined with the detailed input schema and sibling tool names, the context is complete.

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 coverage is 75%, so the schema already documents most parameters. The description adds value by clarifying that layout and caption style can be combined ('and/or'), and by directing users to katto_list_caption_styles for valid caption_style values, which supplements the enum list.

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 a specific action ('Re-render') on a specific resource ('one already-finished clip') and names the exact dimensions being changed ('new reframe layout and/or caption style'). It distills katto_rerender_clip from siblings like katto_create_clip_job by emphasizing the clip is already finished.

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 clear usage context: valid caption styles come from katto_list_caption_styles, and callers should poll katto_get_rerender for the URL. It implies this is for existing clips rather than new job creation, though it does not explicitly state when not to use the tool or name conflicting alternatives.

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