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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds two non-structured facts: the call costs 1 credit and only public collections are accessible. It does not describe pagination behavior despite the cursor parameter, but the annotations carry that lower bar.

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?

Three short sentences, front-loaded with the resource and immediately followed by the identifying constraint and cost. The opening fragment "Collection videos." restates the title and earns little, but the rest is waste-free.

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 5-parameter read tool with no output schema, the description is adequate: it gives the resource, the cost, and the required parameter choice. It leaves unaddressed how to discover a collection_id and how this differs from the playlist siblings, which is the one gap an agent would actually hit.

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 80%, so the baseline is 3, and the description adds a real constraint the schema does not encode: url and collection_id are mutually exclusive alternatives (both are plain optional in the schema). Beyond that it adds nothing for count/cursor/cache_max_age.

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 resource: videos contained in a public TikTok collection, and clarifies what a collection is (creator-curated playlist of others' and own posts). It does not differentiate from the near-identical siblings tiktok_playlists / tiktok_playlistVideos, which is the main ambiguity an agent would face, so it stops short of a 5.

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?

"Pass either `url` or `collection_id`" gives invocation guidance but no when-to-use guidance: it never says how to obtain a collection_id (presumably tiktok_playlists) or when to prefer this over tiktok_playlistVideos. Usage is implied only by the resource name.

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