whatsapp_post_image_status

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

Annotations already cover the safety profile (readOnlyHint=false, openWorldHint=true, idempotentHint=false, destructiveHint=false), so 'Not idempotent' is largely redundant. However, the description adds genuinely new behavioral context: the 24-hour visibility window to allowed contacts and the fact that the status message ID is returned, which matters since there is no output schema.

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?

A single tight sentence, front-loaded with the action and resource, with the source variants, caption, audience, lifetime, idempotency and return value packed in without waste.

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?

With no output schema, the description usefully names the returned status message ID, and it covers visibility, lifetime, and the two input modes. It does not clarify that at least one of url/data must be supplied despite zero required parameters, which leaves a minor 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 all four parameters are already documented, making 3 the baseline. The description's 'from base64 data or a public URL' adds a small amount of disambiguation between the url and data parameters but nothing about mimeType or caption semantics.

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 and resource ('Post an image status (story)'), names both accepted input sources, and specifies the caption and audience/expiry. It is clearly distinguishable from siblings like whatsapp_post_text_status and whatsapp_post_video_status without opening any schema.

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 implies when to use it (posting an image story) and contrasts the two input sources, but never explicitly routes the agent against alternatives such as post_text_status, post_video_status, or send_image. No when-not guidance is provided, so usage is only implied.

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