watch_video

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

With no annotations, the description carries the burden and does well: it discloses that processing is local, that keyframes are deduplicated, that only a first batch of images is returned inline, and that transcribe=false degrades to frames-only. It omits failure modes (unsupported URLs, private videos), duration limits, and whether remote downloads require network access, which 'all locally' leaves slightly ambiguous.

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 lead sentence front-loads the core behavior and return shape before any parameter detail. The Args block is somewhat redundant in structure but justified given zero schema description coverage; nothing is padded or off-topic.

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?

There is no output schema, so the description correctly explains what comes back (transcript plus inline keyframe images) and how to continue fetching frames. For a four-parameter tool with a network/local duality, missing details on video-length limits, supported URL failures, and total keyframe counts keep it short of complete.

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, and it does for all four parameters: source (URL for YouTube/Instagram or a local file path), max_frames with range and default (1-24, default 12), language with concrete example values, and transcribe with the semantic consequence of setting it false. This adds real meaning the bare schema titles do not.

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?

Opens with a specific verb and resource ('Actually watch a video') and enumerates the concrete outputs: scene-aware deduplicated keyframes plus a timestamped transcript. It also distinguishes itself from the sibling get_frames by naming it as the follow-up path for additional 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?

Explicitly routes the agent: this tool returns only the first batch, and 'use get_frames for more frames from the same video' names the alternative and the condition that selects it. It gives no guidance on when to prefer get_transcript or list_watched, so the routing is clear but not exhaustive.

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