send_message

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

With no annotations, the description carries the full behavioral burden and only discloses that the message is sent as the user and that content is text-only. It says nothing about irreversibility of sending, whether the message goes out immediately, authorization or session requirements, rate limits, or what the call returns. For an outward-facing, non-reversible write action this leaves significant gaps.

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?

A single front-loaded sentence with the action first and the parameter detail compressed into a parenthetical. No filler, no restatement of the tool name, nothing that could be cut without losing information.

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 two-parameter tool with no output schema and no annotations, the definition is minimally adequate: it conveys the action, identity, and recipient formats. It is silent on return values, error/ambiguity behavior, and any preconditions, which an agent needs for a send operation.

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 both parameters. It does well on `recipient`, enumerating three accepted formats (jid, phone number with country code, contact name) that the bare string schema does not convey, but `text` is never addressed — no indication of formatting, length limits, or whether media/emoji are permitted. Partial compensation only.

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?

Names a specific verb and resource ("Send a WhatsApp text message") and adds the identity context "as the user," which is meaningful for a messaging tool. It does not name a sibling, but none of the listed siblings send messages, so the action is unambiguous without that comparison.

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?

Usage is only implied: the description establishes that this is the send path while all listed siblings are read or search operations, so an agent can infer when to pick it. There is no explicit guidance on when not to use it, whether confirmation is expected before sending, or what happens if the recipient is ambiguous (contact name matching multiple people).

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