extract_frame_at_timestamp

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

No annotations are provided, so the description carries the burden. It does disclose the output format (base64 JPEG), which is helpful, but it does not mention whether the operation is read-only, what happens for out-of-range timestamps, or any other behavioral constraints. Minimal but not absent.

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 a single, front-loaded sentence that states the action, resource, and output format without any redundancy or filler. Every word 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?

For a simple 2-parameter tool with no output schema, the description covers the core function and return format, but lacks guidance on distinguishing this from many sibling tools (e.g., extract_frames) and does not address edge cases like timestamp bounds or file requirements.

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 100% with both parameters (file_path, timestamp) already described clearly. The description adds no extra parameter details, so the baseline of 3 is appropriate.

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 clearly states a specific action ('Extract a single frame at a specific timestamp') and the resource ('video file'), with an explicit output detail ('base64 JPEG image'). This distinguishes it from sibling tools like extract_frames or generate_thumbnail_grid, which imply multiple frames.

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 phrase 'single frame at a specific timestamp' implicitly suggests when to use this tool over siblings, but there is no explicit guidance, exclusion, or mention of alternatives. The intended use case is implied rather than stated.

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