Video metadata

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

Annotations already cover readOnlyHint, idempotentHint, openWorldHint, and destructiveHint false. The description adds 'fast' and the metadata-only scope, which are useful behavioral traits beyond the annotations and are not implied by them.

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 crisp sentences with no filler. The core purpose and scope are front-loaded, and the second sentence provides actionable usage guidance.

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 simple read-only probe with two fully-documented parameters and strong annotations, the description fully equips an agent to decide when to call it and what it will return. The listed fields substitute for an output schema.

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 100%, with both source and response_format fully described in the schema. The description lists output metadata fields but adds no parameter semantics beyond the schema, 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?

States a specific verb (probe) and resource (video metadata) with concrete fields (duration, resolution, codecs, audio presence). Explicitly excludes transcription and frames, distinguishing it from video_transcribe and video_extract_frames.

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?

Gives a clear when-to-use instruction: 'Use before expensive analysis to plan detail level / time ranges.' It implies exclusions via 'without transcription or frames' but does not explicitly name sibling alternatives, so it falls short of a 5.

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