Create clip

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

With no annotations, the description carries the full behavioral burden and does so: it discloses the transcript prerequisite, the async lifecycle (returns status "preparing", renders in background ~1 minute), the required polling via get_clip, and the distinct duration constraints per mode (3 s–10 min for exact, ≥8 s for ai). This is context an agent cannot get from the schema alone.

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?

Four tight sentences, each earning its place, with the core purpose front-loaded and the routing advice, lifecycle, and constraints following in priority order. No filler or restatement of the tool name.

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?

No output schema exists, and the description compensates by describing the return shape and the polling flow. Slight gaps remain around failure modes (e.g. missing transcript, out-of-range bounds) and permissions, but for a 4-param create tool it is nearly 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 100%, so the baseline is 3, but the description adds real meaning beyond it: numeric bounds for mode=exact (3 s–10 min) and mode=ai (≥8 s) are not present in the schema's enum description. It adds constraints, though it doesn't restate projectId/startSec/endSec semantics.

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+resource ("Add a clip from a time range of the source") and immediately names the sibling it is not (update_clip for existing clips). An agent can distinguish it from update_clip/rerender_clip without opening any 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?

Explicitly routes to the alternative: "To change an existing clip use update_clip instead," and states the prerequisite (needs a transcript) plus the follow-up flow (poll get_clip until done). When-to-use and when-not-to-use are both covered.

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