Download media from a WhatsApp message

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

The description discloses key behavioral details beyond the annotations: it handles four media types, returns small images inline for inspection, saves to disk, and fails with MEDIA_UNAVAILABLE when media has expired. This meaningfully supplements the readOnly/idempotent/destructive hints.

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?

Three concise sentences in a logical order: primary action, inline return nuance, and failure mode. Every sentence earns its place without redundancy or excessive length.

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 description adequately covers the tool's behavior, error case, and side effects. Combined with complete schema parameter descriptions and safety annotations, an agent has all necessary information to invoke it correctly for any supported media type.

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?

Parameter documentation is already complete in the schema (100% coverage). The description adds no parameter-specific meaning beyond what the schema provides, but it does add useful context about inline image return and the error condition. A baseline of 3 is appropriate for full schema coverage.

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 uses a specific verb ('Download'), names the exact resource (photo/video/audio/document attached to a message), and states the destination (disk on the machine running wazap). This clearly distinguishes it from siblings like send_media and get_message, which target different operations.

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 gives clear context for when to use the tool: when a message has media that should be saved or viewed. It does not explicitly name alternatives or exclusions, but the schema's 'has_media=true' hint and sibling names make the intended use apparent. There are no misleading usage signals.

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