Keyframes

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

Annotations already establish this as a read-only, closed-world operation, so the bar is lower; the description adds real domain context by explaining that lossless cuts start at keyframes and that cut points snap to them. It omits operational details such as result ordering or what happens when the default limit of 500 truncates the list.

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?

Three short sentences, purpose front-loaded, followed by the practical rationale and the parameter hint. No filler or restatement of the title.

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?

The tool is simple and read-only, and the description covers purpose and the 'near' behavior, but there is no output schema and the description never indicates the shape of the return value (a list of timecodes). For a listing tool whose consumers must interpret results, that leaves a meaningful gap.

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?

With 60% schema coverage, the schema documents path, start, end, and limit, but 'near' has no description in the schema at all. The description fills precisely that gap by defining it as returning keyframes around given times, which is the key semantic an agent needs to use it correctly.

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 opens with a specific verb and resource: 'Lists video keyframes.' It is unambiguous what the tool returns, but it does not explicitly contrast itself with siblings like view_frames or detect_scenes, which an agent might otherwise consider for similar inspection tasks.

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 gives concrete usage context ('use this to choose cut points or to see where a cut will snap') and explains when to use the 'near' parameter. It does not name an alternative tool or state when not to use it, so it stops short of full routing guidance.

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