Media Metadata

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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint, so the safety profile is covered. The description adds genuinely new context beyond them: the credit cost per call and the fact that no file download occurs, which matters for cost-sensitive agents. It stops short of describing return content or any rate/URL-support limits.

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, front-loaded with the capability and followed by the cost constraint. The opening "Media Metadata." merely restates the title and could be dropped, but the rest is waste-free.

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 2-parameter, no-output-schema tool, the description covers input intent and cost but never indicates what metadata is returned (title, thumbnails, duration, formats), which the agent cannot learn from a missing output schema. Adequate but with a clear gap.

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 `query` (with an enumerated list of supported platforms) and `fields` (dot notation, no credit impact) are fully documented in the schema. The description adds nothing beyond that, so the baseline of 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?

The description gives a specific verb+resource ("Extract metadata from a media URL") and a key differentiator ("without downloading the file"), which clearly separates it from audio_download and video_download. It does not name siblings explicitly, but the purpose is unambiguous.

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 "without downloading the file" implicitly signals when to prefer this over the download tools, and the credit cost sets expectations. However, there is no explicit when-to-use/when-not guidance and no sibling is named, so the agent must infer the routing.

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