Zoom into a segment

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

Annotations only declare readOnlyHint and openWorldHint=false; the description adds real behavior beyond that: a hard 48-frame cap and adaptive sampling density, plus that output is a dense frame series rather than a summary. It does not state the return container or whether frames come back as images vs paths, which keeps it from a 5.

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 sentences, zero filler, and the highest-value facts (frame cap, motion-detection purpose, workflow position) are front-loaded. Every clause carries information the 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 5-parameter tool with a nested crop object and no output schema, the description covers purpose, the frame budget, and workflow placement, while the schema fully documents crop and fps. The main remaining gap is what the caller receives back (frame images, list of paths, or a bundle), which the agent may need before chaining further calls.

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; the description earns above that by telling the agent where start/end values should originate (watch_video's timeline) and by framing the segment as short. fps and crop semantics are left entirely to the schema, which already documents them well.

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 action and resource: dense consecutive frames of a short segment, capped at 48, and names the intent (motion: flickering bug, animation, quick transition). That intent clause cleanly separates it from the sibling 'frame' (single frames) and 'watch_video' (whole-video pass).

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?

Explicit sequencing: 'Use after watch_video, with start/end taken from its timeline' tells the agent exactly when in the workflow to call it and where the arguments come from. It stops short of naming an explicit when-not/alternative (e.g. 'for a single still use frame'), so it is clear context rather than full routing guidance.

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