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

With no annotations, the description carries the full burden and does it well: it discloses that files are written to disk, HD selection when exposed, magic-byte verification of downloads, and the no-auth requirement. It does not cover overwrite behavior for an existing out_dir, rate limits, or failure modes beyond noting an errors field in the returned envelope.

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 action and resource, followed by the return payload. Parenthetical qualifiers ('HD when exposed', 'all magic-byte verified') earn their space, though the second sentence packs a long field list that borders on dense.

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?

No output schema exists, so the description compensates by enumerating the manifest envelope contents (author, title, stats, music identity, media URLs, local files, errors, decode-slot provenance), and it covers the auth precondition. Only minor gaps remain, such as out_dir overwrite behavior and any rate-limit expectations.

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 schema already documents url, out_dir, and download_media, making 3 the baseline. The description adds mild value by restating accepted URL forms and clarifying that the video, soundtrack and covers all land in out_dir, but it introduces no syntax or format detail the schema lacks.

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?

Names a specific verb (Harvest) and resource (public TikTok video), enumerates what is fetched (video in HD, soundtrack, covers) and what is returned. It implicitly contrasts with lookup_video by emphasizing downloading rather than just metadata, but never names a sibling explicitly, so differentiation is left to inference.

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 gives a precondition ('given a video/photo URL, short link or bare video id') and a note that no login or API keys are needed, but offers no when-to-use/when-not guidance and never mentions lookup_video or read_manifest as alternatives. An agent choosing between harvesting, looking up, and reading a manifest gets no routing help.

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

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

No annotations are provided, so the description carries the burden. It discloses the return artifact (a draft-07 JSON Schema) and the contract version, and 'Return' plus zero parameters makes the read-only, side-effect-free nature evident. It doesn't describe error cases, but for a static schema fetch that is a minor omission.

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?

One sentence, front-loaded with the artifact and its standard, with the usage hint trailing. No filler or redundancy.

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 zero-parameter, read-only schema-retrieval tool with no output schema, the definition covers what is returned and why. A note on sibling boundaries (schema vs. actual manifest data) would make it complete.

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 tool takes no parameters, so per the baseline a 4 is appropriate. The description correctly implies a parameterless call and spends its wording on what is returned instead.

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 (Return) and resource (JSON Schema draft-07 for the video_manifest envelope), and pins the contract version (schema_version 1.0). It is distinguishable from read_manifest by being the schema rather than the data, but it never explicitly names that sibling boundary.

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 use context ('use it to validate or explore the output contract'), which tells the agent when the tool is relevant. It stops short of stating when not to use it or pointing to alternatives like read_manifest for actual content.

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

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.

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

No annotations are provided, so the description carries the burden. It usefully discloses an unexpected guardrail ('Refuses any file not named video_manifest.json') and the return shape ('full envelope'), but says nothing about error behavior, permissions, or what the envelope contains beyond the vague term.

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 tightly written sentences with no filler, and the core purpose is front-loaded before the constraint clause. Every clause 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 single-parameter read with no output schema and no annotations, the description covers purpose, provenance, and the naming guardrail adequately. It could note failure behavior or envelope contents, but nothing essential is missing.

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 a single documented 'path' parameter, so the schema already does the work. The description adds only an implicit naming constraint on the target file, not syntax or format detail beyond what the schema provides, so the baseline 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 names a specific verb (Read) and resource (video_manifest.json) and clarifies the file's provenance ('produced by a previous extract/lookup'), which distinguishes it from the sibling extract_video and lookup_video tools. An agent can identify the operation without opening the 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?

It clearly situates usage after an extract/lookup and states what it returns, implying when to reach for it. It stops short of naming an explicit alternative or saying when NOT to use it, so it is clear context but not full routing guidance.

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