lookup_video

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

No annotations exist, so the description carries the full burden and does disclose the key traits: metadata-only, no media files written, fast, and restricted to public videos (implying private/auth-gated videos are unsupported). It also enumerates the returned fields. It does not mention failure modes, rate limits, or auth requirements, keeping it below 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, front-loaded with the distinguishing claim, and every clause (pipeline equivalence, return fields, no-write guarantee) adds information. The internal CLI-flag reference ('--no-download') is slightly jargon-heavy but earns its place as the fastest contrast with extract_video.

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?

With no output schema, the description compensates by listing what comes back (author, title, stats, music identity, media URLs), which is the right call for a metadata lookup. A note on private-video behavior or error cases would close the remaining gap; for a simple two-parameter read tool this is nearly sufficient.

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% with only two parameters, so the schema already documents url and out_dir fully; baseline is 3. The description adds one small clarification — that out_dir holds the manifest — but no format or syntax detail beyond the schema.

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 verb+resource ('metadata-only lookup of a public TikTok video') and immediately differentiates from the sibling by noting it is 'the same decode pipeline as extract_video but with --no-download'. An agent can tell exactly which of the two extraction tools to pick without opening either 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?

Gives a clear selection rule: 'Use this when you only need to read the video,' framed against extract_video's download behavior. The exclusion (use extract_video if you need media files) is implied by the --no-download contrast rather than stated outright, so it falls just short of an explicit when-not.

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