whatsapp_post_video_status

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

Annotations already declare readOnly=false, idempotent=false, destructive=false and openWorld=true, and the description reinforces non-idempotency plus adds genuinely new behavior: the 24-hour expiry, audience scope (allowed contacts), and the return value (status message ID). That is useful context beyond the annotations, though it doesn't cover failure modes or size/format limits for large base64 payloads.

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?

One sentence, front-loaded with the action and media type, followed by the source, caption, visibility, idempotency and return-value facts. No filler.

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 4-parameter tool with no output schema and 0 required parameters, the description supplies the essentials: source options, caption, visibility, non-idempotency, and the returned ID. It stops short of clarifying the url/data exclusivity or any media constraints, which leaves a small gap for an agent assembling the call.

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 the baseline is 3. The description adds the important nuance that url and data are alternative sources for the video and that caption is optional, but does not resolve whether the two source parameters are mutually exclusive or which wins if both are supplied.

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+resource ('Post a video status (story)') and immediately distinguishes itself from the text/image status siblings by naming the media type. It also clarifies accepted sources (base64 data or public URL) and the optional caption, so an agent knows exactly what this tool does.

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?

Provides clear context for use: visibility is restricted to allowed contacts and lasts 24 hours, matching the ephemeral-status semantics of the sibling post_text_status/post_image_status tools. It does not explicitly say 'use this instead of post_text_status when the payload is a video,' but the media-type framing makes the routing obvious.

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