video_info

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

With no annotations provided, the description carries the full burden. It discloses the 'without downloading' behavior for URLs, which is valuable, but omits other relevant traits like potential network dependencies, permissions, failure modes, or whether operations are read-only in an explicit manner. It provides some context but not comprehensive behavioral transparency.

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?

The description is concise and well-structured: a clear opening sentence, a short breakdown of metadata by source type, and a compact Args section. Every sentence contributes to understanding without redundancy or verbosity.

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?

Given the output schema exists (though not shown), the return value structure is presumably covered elsewhere. The description effectively explains the two input scenarios and what metadata to expect, covering the key usage context. Minor gaps like error handling or limitations are not critical for a metadata tool and can be assumed.

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 0%, so the description must compensate. It defines the sole parameter 'source' as either a local file path or a video page URL, giving concrete examples (YouTube, Vimeo). This adds meaningful semantics beyond the bare schema, though it does not delve into format constraints or edge cases.

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 clearly states the tool's purpose: getting video metadata, and it delineates two source types (local files vs URLs) with distinct metadata fields. While it does not explicitly differentiate from siblings like media_probe, the verb+resource is specific and 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 description says what the tool does for local files and URLs, but provides no guidance on when to choose this over other sibling tools such as media_probe or video_download. It does not state exclusions, prerequisites, or alternative conditions, so an agent has to infer when this is the right choice.

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