douyin_video_detail

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

With no annotations, the description carries the full behavioral burden and does disclose the key trait that login is required before this call succeeds. It also implies a read-only retrieval and highlights a watermark-free direct link as a distinguishing output. It omits failure modes when unauthenticated, rate limits, and pagination/return shape details.

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 dense sentences, front-loaded with the returned fields and followed by the prerequisite and ID source. No filler, no restatement of the tool name, and the bolded key output is easy to scan.

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 read tool with no output schema, the field enumeration substitutes well for a documented return contract, and the login prerequisite is captured. Missing only error/edge behavior (unauthenticated failures, expired login) that an agent would need before invoking.

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 baseline is 3, but the description adds meaning beyond the schema by specifying the provenance of aweme_id (from search results, user profile, or a share link), which helps the agent source the required value correctly. The account parameter's default behavior is already documented in 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 (retrieve a single Douyin work's details) and enumerates the exact payload: caption, author, publish time, engagement data, cover, watermark-free play link, share page URL. This distinguishes it from siblings like douyin_search_videos and douyin_user_profile, which return lists rather than one work's detail.

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?

Tells the agent the precondition ('需要已登录') and where aweme_id comes from (douyin_search_videos / douyin_user_profile / share link), which is real routing guidance to sibling tools. It stops short of an explicit when-not-to-use or a note on choosing douyin_parse_share_link for URLs, so it is clear but not exhaustive.

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