waba_reply

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

With no annotations, the description carries full burden. It discloses the 24-hour validity constraint and the API rejection behavior, which is critical. It doesn't mention return format or error details, but the core behavioral trait (time window) is clearly stated.

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?

Two sentences with zero waste. The purpose is front-loaded, then the critical constraint is stated immediately, followed by the alternative. Every word earns its place.

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 simple reply tool with full schema coverage, the description covers the essential usage context (24-hour rule, alternative). It doesn't explain return values, but given no output schema and the tool's simplicity, this is a minor gap. Overall it's sufficient for correct invocation.

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 description doesn't need to add parameter detail. It doesn't add new semantics beyond the schema; the message object structure is already fully described in the schema. Baseline 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 tool's function: replying with free-form text or media via the official API. It also distinguishes it from template-based sending by explicitly stating the 24-hour restriction, which differentiates it from siblings like send_waba_template.

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 explicit when-to-use guidance: only within 24 hours of the customer's last message, and advises checking waba_list_conversations first. It also states the alternative (send a template) for outside that window, making routing unambiguous.

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