video_trim

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

Beyond the annotations (destructiveHint=true, non-idempotent), the description discloses that stream copy is fast and lossless, that cuts snap to keyframes, and that an existing output is never overwritten unless overwrite=true. The keyframe caveat is exactly the kind of behavioral trait an agent could not infer from structured data.

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 tightly packed sentences, front-loaded with the operation and immediately followed by the two facts that affect correctness (losslessness/keyframes, overwrite safety). No sentence is filler.

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?

An output schema exists, so return values need not be described, and the safety profile is covered. The remaining gap is the meaning of start/end (units, null end, inclusivity) for a destructive tool with zero schema documentation, which the description leaves unresolved.

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% across 5 parameters, so the description must compensate and only partly does: it explains overwrite semantics but never gives units or meaning for start/end, nor what a null end implies (presumably trim to end of file). input_path/output_path are self-evident but undocumented.

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 states a specific verb and resource ("Cut a section out of a video into a new file") and names the mechanism (stream copy). An agent can distinguish this from siblings like video_info, video_thumbnail, or video_to_gif 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?

The use case is implied clearly (extracting a segment to a new file), but no alternative is named and no when-not condition is stated. The keyframe caveat functions as a soft usage boundary, yet the description never says what to do when frame-accurate cuts are required.

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