get_v1_media_video_download_by_id

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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the description is not carrying the safety burden. It still adds genuinely useful non-obvious context: it returns a URL plus the HTTP headers to send, the file itself is not downloaded, and each call is a live, billed TikTok request. It stops short of describing failure modes or auth/rate-limit specifics, so not 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?

Front-loaded with the core purpose, then return behavior, then parameter note, then sibling routing, then cost. Every sentence earns its place, though the trailing '(GET /v1/media/video/download/by/id)' endpoint restates the name and is mildly redundant.

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 two-parameter read-only fetch with no output schema, the description covers what the tool returns (URL + headers), what it does not do (no file download), the watermark toggle, cost, and sibling selection. Nothing an agent needs to call it correctly 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 only 50%: `id` is documented with a pattern and example, but `watermark` has no description in the schema. The description fills that gap directly by explaining the default-true behavior and that it 'selects the watermarked version', which is exactly the missing semantics.

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+scope: 'Get a download link for a TikTok video by video id', and explicitly distinguishes itself from the URL variant and the music-track sibling. An agent can tell it apart from get_v1_media_video_download_by_url 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?

Names two alternatives with the exact condition that selects each: 'Use `get_v1_media_video_download_by_url` when you have a link and `get_v1_media_music_download_by_id` for the audio track only.' Nothing is left to inference.

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