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

Goes well past the annotations by disclosing cost ('Free'), the dry-run/confirm gate that spends nothing, the hard cap of 30 videos per call, and the UI behavior that the grid card fills in as videos render. These are exactly the operational facts an agent needs before invoking a non-readOnly tool, and none of them are derivable from the annotation set.

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?

Front-loaded with purpose and cost, then inputs, then the confirm contract, then limits and UI feedback - a sensible priority order with almost no filler. The stacked parentheticals (the influencer-id aside, the footage alternatives) make a few sentences denser than they need to be, but nothing is wasted.

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 10-parameter mutation tool with an output schema, annotations, and full schema coverage, the description supplies the missing pieces: cost, the confirm gate, batch limits, and the clips-vs-character alternative. It stops short of covering failure/partial-render behavior or whether clip ids must belong to the workspace, which would round it out.

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 already 100%, so the baseline is 3; the description earns above that by explaining the relational semantics the schema cannot - that each hook is applied to every clip, that clips and character are alternatives (up to 10, newest first), and that footage may be omitted when the app is on file. It does not restate music or upload-id params, but those are fully described in the 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?

States a specific verb and resource ('several finished videos at once') and immediately defines the cross-product semantics: every hook on every clip sharing the same footage. It explicitly distinguishes itself from the singular sibling make_video, so an agent can route between them without opening either schema.

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?

Gives concrete prerequisites (clip ids or an influencer id, 1-10 hook lines, footage in the make_video forms) and an explicit two-phase contract: without confirm true it only returns the pairs and spends nothing, with confirm true it starts rendering. It does not explicitly say when to prefer make_video over this tool, but the 'several at once' framing plus 'like make_video' makes the split clear.

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