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

Annotations cover only read-only and non-destructive hints. The description adds substantial behavioral detail: the required permission (whatsapp_recordings:read), the need to reauthorize to refresh, the retention cap, the presence of urlExpiresAt for expiration, and the exclusion of Maya calls. These go well beyond the structured fields.

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?

Four short sentences, each carrying unique information: primary action, permission, refresh/expiration behavior, and scope exclusion. The main purpose is front-loaded, and there is no redundant or filler text.

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?

Given a single-parameter, read-only tool with an output schema, the description adequately covers purpose, permissions, retention, expiration, and scope. The only notable gap is the lack of explicit guidance on how to obtain or interpret callId, which is not explained despite the 0% schema coverage.

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 0%, so the description must compensate for the undocumented callId parameter. It does not explain what callId refers to, where to obtain it, or how it relates to the recording. The description merely implies the parameter through the tool's purpose, leaving the agent to infer its meaning.

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 states a specific verb ('Request') and resource ('private WhatsApp recording playback/download URL'), clearly distinguishing it from sibling tools like get_whatsapp_call_transcript or download_whatsapp_document. The explicit 'Does not grant access to Maya calls' further narrows its scope against another call system.

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?

It provides clear context: the tool returns a private URL, requires specific permission, has retention/expiration behavior, and is explicitly not for Maya calls. However, it does not name alternative sibling tools (e.g., use get_whatsapp_call for metadata), so it stops short of full alternative guidance.

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