capcut_set_speed_curve

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

With no annotations, the description carries the full burden and does well: it discloses the dry-run default, the Pro-tab caveat in CapCut 9.5, that export may require Pro, the null=1x reset, and the clip-length math (source / average speed, snapped to frames). It stops short of covering failure modes or what the dry-run plan contains.

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?

Dense but front-loaded: the core action and its options come first, followed by caveats and the dry-run default. Some clauses are run-on, but every sentence carries information an agent needs.

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 mutation tool with no annotations and no output schema, the definition covers the critical behavioral facts (dry-run default, Pro requirement, reset semantics, length recomputation). Only the shape of the returned plan/response is unaddressed, which is minor given the dry-run framing.

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 only 50%, so the description has to compensate, and it does for the important parts: it defines the preset enum beyond the bare list, the custom-points shape (x 0..1, speed 0.1..10), and the null meaning. It leaves track and draft largely to the schema but adds real meaning over the raw fields.

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: setting a speed curve on one video clip identified by start_s. It enumerates the preset options and the custom-points form, so it is clearly distinguishable from siblings like capcut_set_clip or capcut_set_timeline.

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?

It explains the modes of the tool itself (preset vs custom points vs null-to-reset) and that dry-run is the default, which is useful. However, it never says when to reach for this tool instead of neighbors such as capcut_set_clip or capcut_add_keyframes, so sibling routing is left to inference.

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