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

Annotations already indicate it is not read-only, not destructive, and idempotent; the description adds useful behavioral context by explaining it re-delivers a previous order and requires an active session. It does not contradict the annotations and gives the agent an accurate picture of the operation's side effect: a message is sent to the buyer.

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 concise sentences: the first states the action and resource, the second states when to use it and the prerequisite. Every sentence adds essential guidance with 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?

For a single-parameter, idempotent delivery tool with no output schema, the description provides the necessary decision and invocation context: what action, for which orders, under what condition, and what to do first. Nothing important is missing.

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 schema already fully documents the 'id' parameter as an order UUID with 100% coverage. The description adds meaning by clarifying that the ID must refer specifically to a paid-but-undelivered order, which constrains the acceptable value beyond the schema's generic UUID description.

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 action, 'Re-send', tied to a clearly defined resource, 'a paid-but-undelivered order', and names the delivery channels. This differentiates the tool from nearby siblings such as refund_order or list_orders because it targets the delivery-retry case specifically.

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 gives an explicit trigger condition: use when a sale settled while no WhatsApp session was connected, and it gives a prerequisite ordering: connect one first, then deliver. It does not explicitly name alternatives or exclusions, but the condition is specific enough to guide selection.

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