Caption Variants

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

Annotations mark this as a non-readonly, non-idempotent write with openWorldHint, and the description usefully adds that each copy gets a new clip id — the key behavioral consequence for an agent tracking outputs. It also discloses the plan gating and the 3-per-clip bound. It omits whether the operation is synchronous or whether copies cost credits quota.

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?

Two short sentences, front-loaded with the action and bounded by the key constraints (plan tier, count limit, new clip id). No wasted words and no redundancy.

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 simple 3-parameter mutation with no output schema, the description covers what is produced ('each copy is a new clip id'), the eligibility gate, and the quantity cap. It lacks any mention of async behavior, rate limits, or error conditions, which is the only meaningful gap given this tool's complexity.

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 description coverage is 0%, so the description must carry the load. It clarifies styleIds implicitly ('caption styles', at most 3), but says nothing about clipId or projectId beyond their names. The enum of valid styles and the maxItems/minItems bounds live only 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: 'Render copies of a clip in up to 3 other caption styles.' An agent can distinguish this from make_clip or rename_clip from the description alone. It stops short of explicitly naming sibling tools that also create clips, but the caption-style framing is precise.

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 real usage context: Pro/Studio plan requirement and a hard cap of 3 styles per clip. However, it never says when to prefer this over make_clip or other clip-creation siblings, nor does it mention failure modes when the plan lacks entitlement or the clip already has variants.

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