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

The description discloses that the tool fires a callback, posts to WhatsApp, and enforces exactly-once semantics with first-wins and 410 for later responses. It also notes the API key requirement. These details supplement the annotations, which only indicate readOnly=false and non-idempotent.

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 dense sentences, front-loaded with the core action, no filler.

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 covers purpose, side effects, exactly-once semantics, and auth, but lacks explicit mention of successful return value or response format (no output schema provided). Still, it is quite complete for a mutation tool.

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 coverage is 100%, so the baseline is 3. The description adds minimal parameter-specific detail beyond schema (e.g., it doesn't elaborate on reason or responderName), though it does confirm the decision values implicitly.

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 it approves or rejects a pending approval programmatically, distinguishing from WhatsApp reply and from sibling tools like request/cancel/reflection actions. It specifies the resource (pending approval) and the action (decide).

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 context for when to use (MCP instead of WhatsApp) and the exactly-once behavior warns of potential 410 errors for duplicate responses. However, it doesn't explicitly name alternative tools or exclude usage for reflection approvals, leaving some ambiguity with sibling tools.

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