media_extract_frames

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds a key safety guarantee: 'Source media is never modified.' It also explains the sampling behavior (evenly-spaced, fps overrides count). While it does not mention potential file overwrites or directory creation, it gives substantial behavioral context beyond the bare operation.

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?

The description is concise and front-loaded with the primary purpose. It uses only two short sentences to convey core functionality, parameter selection logic, and safety behavior. No redundant or irrelevant content; every sentence earns its place.

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?

Given that an output schema exists, the description need not explain return values. It covers the tool's core behavior, parameter semantics, and safety characteristics. It omits edge-case behavior (e.g., overlapping output files), but overall it provides sufficient context for a 4-parameter tool with clear schema support.

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?

The input schema already provides 100% parameter coverage, including descriptions for fps, count, file_path, and output_dir. The description reiterates the count/fps relationship already present in the schema descriptions, adding no new parameter-level detail. Baseline score of 3 applies since the schema does the heavy lifting.

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: 'Extract multiple frames to an output directory for review.' It clearly distinguishes from the sibling tool media_extract_frame by emphasizing 'multiple frames'. The scope (output directory) is also stated, leaving no ambiguity about what the tool does.

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 description provides clear guidance on choosing between count and fps parameters, explicitly stating that fps overrides count and count is default. However, it does not explicitly address when to use this tool versus the sibling media_extract_frame, leaving that to be inferred from the word 'multiple'. Thus usage guidance is implied rather than explicit about alternatives.

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