Send a text message

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

The annotations already flag destructiveHint=true and openWorldHint=true, and the description reinforces this with 'Send a real text message', implying an actual external side effect rather than a simulation. It adds the return value ('Returns a request ID'), which matters given no output schema, but it discloses nothing about irreversibility, cost, rate limits, or what keep_record=false deletion actually means.

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 short sentences, action first and return value second, with no filler. Nothing could be removed 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 simple four-parameter tool this covers the essentials, including the return value that the absent output schema would otherwise leave blank. However, as an irreversible outbound-action tool it omits delivery semantics, error behavior, and any warning about the real-world consequences of sending.

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 100%, so the parameters (phone, text, keep_record, schedule_minutes) are already fully documented in the schema. The description only reinforces the single-recipient constraint of 'phone'; it adds no meaning about scheduling or record retention.

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?

States a specific verb and resource ('Send a real text message to one phone number'), which is enough to separate it from the call_* siblings that dial rather than text. It does not explicitly name any sibling, so differentiation is implicit rather than stated.

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?

There is no guidance on when to use this versus alternatives such as call_text or call_ivr, and no stated preconditions (consent, verified number, delivery windows) before firing a real message. The agent is left to infer usage entirely from the name.

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