get_metadata

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

With no annotations, the description carries the full transparency burden. It discloses the async behavior (poll check_metadata), that no media is downloaded, and that it works across 1000+ sites. It does not mention auth or rate limits, but the core non-blocking pattern is well conveyed.

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 sentences, each earning its place: the first lists fields, the second covers site breadth, the third covers async flow and alternative tool. Front-loaded with the main verb and resource, no redundancy.

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 single-parameter tool with no output schema, the description is self-sufficient. It explains the full lifecycle (submit URL → get jobId → poll check_metadata), lists expected metadata fields, and gives context on which sites work.

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 schema already describes the url parameter with a concrete example, so baseline is 3. The description adds the 'video/audio URL' qualifier and lists supported sites, clarifying accepted input beyond the schema's generic 'Media page URL'.

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 starts with 'Extract full metadata for a video/audio URL' – a specific verb and resource followed by a list of returned fields. It differentiates from the sibling get_basic_metadata by emphasizing 'full metadata', making the tool's unique purpose clear.

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?

Explicitly instructs to prefer get_basic_metadata for lighter needs ('For just title/duration/thumbnail, prefer the faster get_basic_metadata') and tells the agent to poll check_metadata with the returned jobId for results. This is clear when-to-use and alternative guidance.

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