Send Media Message

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

Annotations already indicate this is a write operation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds the useful constraint that the media URL must be publicly accessible, but it does not disclose other behavioral details such as error handling, file size limits, or state changes.

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 concise and front-loaded: the first sentence gives the purpose and scope, the second adds the critical prerequisite. No redundant or filler content.

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 6-parameter tool with full schema coverage and no output schema, the description plus schema are sufficient. It covers the main purpose, media types, and the key constraint. Minor details like file size limits or supported formats are not mentioned but are not essential.

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?

The input schema provides 100% description coverage for all six parameters, including captions, file names, and enum values. The description adds no new parameter semantics beyond reinforcing the public URL requirement, so a baseline score of 3 is appropriate.

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 (send), the resource (WhatsApp media message), and specifies media types (image, video, or document), which distinguishes it from sibling tools like send_audio and send_text.

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 mentions a prerequisite (publicly accessible URL) and the media type enum implies when to use this tool, but it does not explicitly state when to prefer this over alternatives or provide exclusions. No direct comparison to sibling tools is given.

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