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

The description reveals critical behavior beyond minimal annotations: the draft is editable, expires after 30 days, and the 'Director paces scenes and captions to match mood and pace.' It also gives insight into effect usage (e.g., what reads as professional vs. novelty). Annotations provide little, so the description carries the burden and delivers.

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 front-loaded with the main purpose. It is relatively concise given the amount of advice, though some sentences could be merged. It is appropriately sized.

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?

Covers the main action and behavioral aspects, but lacks explicit information about the return structure beyond an 'edit link.' Given the tool's complexity (9 parameters, nested objects, no output schema), a more complete description would state the response format or link to documentation.

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 low (33%), so the description compensates with practical guidance on effect choices (e.g., 'fade, rise and pop read as professional; scatter, slam and glitch read as novelty') and composition advice. It adds significant value beyond the schema, though it doesn't detail every parameter individually.

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 it creates a 'complete, editable lyric-video or story-video draft and get back an edit link.' The verb 'create' and resource 'story draft' are explicit. It distinguishes from sibling tools ('get_spec', 'list_visual_presets') by being a creation action.

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?

Provides clear advice: 'Prefer script mode (one beat per line) unless exact timings are known.' Also warns about draft expiration (30 days). While it doesn't explicitly exclude alternatives, sibling tools are not alternatives for creation, so this suffices.

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