whatsapp_upload_media

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

With no annotations, the description must disclose behavioral traits. It mentions uploading (mutation) but omits details like error handling, rate limits, overwrite behavior, or authentication requirements (though bearer_token is in 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?

The description is very concise (13 words) and front-loaded with the core purpose. While lacking structure, it earns its place for a simple tool, though it could benefit from additional details.

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?

The tool has 5 parameters, no output schema, and no annotations. The description fails to cover output format (media ID structure), error cases, or supported MIME types. It is insufficient for an agent to use reliably.

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 low (40%). The description does not explain the parameters beyond the schema, failing to compensate for the gap. Only media_url and mime_type have descriptions in the schema, but the tool description adds no value here.

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 action: 'Upload a media file to WhatsApp' and specifies the output: 'get a media ID for use in messages.' This distinguishes it from sibling tools like whatsapp_send_media and whatsapp_get_media.

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 this tool is a prerequisite for sending media messages, but it does not explicitly state when to use it versus alternatives or provide any exclusions. The phrase 'for use in messages' gives context but lacks direct guidance.

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