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

With no annotations supplied, the description carries the behavioral burden. It meaningfully discloses the important output behavior: it returns a page_url link, not a direct media URL, which prevents the agent from expecting media content. It does not mention errors, auth, or rate limits, but those are less critical for a simple metadata 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?

Two short sentences with no filler. The first sentence states the purpose, and the second adds the essential output caveat about page_url versus direct media URL. Every word earns its place.

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?

The input side is fully covered by one documented required parameter. There is no output schema, but the description partially fills that gap by naming the key return value, page_url. It could describe the metadata fields or page_url format more explicitly, but nothing needed to invoke the tool correctly is missing.

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?

The input schema already documents `hash` as 'Video hash (8+ hex chars)' with 100% coverage, and the description only repeats 'by hash.' The description adds no new meaning beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 states a specific action ('Fetch metadata'), a concrete resource ('one NudiTok video'), and the lookup key ('by hash'). This clearly distinguishes it from sibling list/search tools such as get_feed, get_trending, and search_content.

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 phrase 'for one NudiTok video by hash' clearly establishes the condition for use: when the agent has a video hash and needs that video's metadata. It does not explicitly contrast with sibling tools, but the single-video-by-hash context is clear and effectively excludes list or search use cases.

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