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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description adds meaningful context by specifying that the links are watermark-free, come in two resolutions, and bundle auxiliary assets (audio, cover, metadata). It stops short of describing failure behavior for non-public or removed videos, which matters for an open-world fetch.

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?

A single front-loaded sentence with the verb first and the returned assets enumerated in a compact list. There is no filler and nothing to trim.

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 one-parameter read tool with no output schema, the description carries the return-value burden well by listing the fields produced. It is only slightly short of complete because it does not describe the response container or how the two resolutions are surfaced.

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?

With one parameter at 100% schema coverage, the schema already documents the url and even supplies an example. The description only reinforces that the URL must point at a public video, adding no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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 and platform-scoped resource ('Get no-watermark MP4 links ... for a public TikTok video') and enumerates exactly what comes back (HD/SD MP4, music track, cover image, title, author). The TikTok naming alone separates it from facebook_download_links and pinterest_download_links without opening any 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?

The word 'public' implies a precondition (the target video must be publicly accessible), which is useful selection context. However, it never states when to prefer this over the sibling download tools or what to do for private/deleted posts, leaving usage to inference.

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