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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and network profile is covered. The description adds the input restrictions and the note that the output is a share link plus share text, but says nothing about link expiry, rate limits, or auth requirements. With annotations carrying the safety burden, this is adequate but thin.

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?

One sentence with three semicolon-separated clauses: purpose first, then the ID alternative, then the detail-tool alternative. No filler, no repetition, and the primary action is front-loaded.

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?

An output schema exists, so return values need not be explained, and the single parameter is fully documented. Alternatives and exclusions are covered. The only gap is behavioral detail about the generated link (e.g., validity/expiry), which would help an agent downstream but is not required to call the tool correctly.

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% and the single url parameter's schema description already enumerates accepted forms and the play-URL/profile-URL exclusions. The description largely restates that same guidance, so it adds little meaning beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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?

The description gives a specific verb+resource: it generates a Douyin share short link AND a full share text from a works page URL, short link, or share text. It explicitly distinguishes itself from the sibling douyin_get_video_share_link_by_aweme_id ("已知 aweme_id 时使用 ID 入口") and from the detail tools ("读取作品内容请使用详情工具").

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?

It states the routing rule twice-conditionally: use this URL entry when you have a page link/short link/share text, use the ID entry when aweme_id is already known, and use the detail tool when the goal is reading content. Exclusions (don't pass play_resource links or profile URLs) are also named.

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