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

With no annotations, the description carries the full burden and does well: it discloses the return shape (one native itemList with video, creator, music, engagement fields), that similarity and ordering are TikTok's rather than a computed score, and the paging behavior (one request, no automatic pagination, no cursor support). It stops short of stating auth or rate-limit behavior, but the operational traits it does cover are substantial.

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?

Four sentences, each carrying distinct information: purpose, return shape, sibling differentiation, and paging/ordering behavior. Front-loaded with the core action and no filler.

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 no-annotation, no-output-schema tool, the description supplies exactly the missing context: return fields, ordering provenance, and pagination limits. Nothing needed to invoke it correctly is absent.

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 description coverage is 100%, so both parameters are already documented (count 1-30 default 10; video_id sourced from search or detail). The description only restates the seed video_id concept and adds no syntax or semantics beyond the schema, so 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 resource ('Get TikTok's recommended videos for one seed video_id') and explicitly distinguishes itself from the sibling related_videos by describing the different mechanism (video-to-video vs topic lookup plus keyword search). An agent can disambiguate from the many sibling tools without opening a 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 description names the alternative (related_videos) and characterizes its different behavior, giving the agent a basis for choosing. It does not state an explicit 'use this when / not when' condition, but the contrast is clear enough to route correctly.

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