send_sms

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

With no annotations provided, the description bears full burden. It discloses delivery speed ('seconds'), no need for telecom accounts, payment via Bitcoin Lightning, and the auto-appended disclaimer. Missing details like error handling or delivery confirmation, but adequate for the tool's simplicity.

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?

The description is concise at several sentences, each adding unique information. It front-loads the primary purpose and flow, followed by constraints. No redundant or vague statements.

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?

Given the tool has 3 required parameters, no output schema, and no annotations, the description covers the workflow, prerequisites, and key constraints (matching values, disclaimer). It does not describe return values, but that is acceptable without an output schema. Overall, it sufficiently informs an AI agent 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 each parameter has a description. The description adds value by clarifying that paymentId must be paid, phoneNumber/message must match create_payment, and the message length includes an appended disclaimer. This goes beyond the schema docstrings.

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 sends SMS messages for real-world coordination, distinguishing it from other communication tools like send_email or send_fax. The verb 'Reach a human via SMS' is specific and the resource is unambiguous.

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 provides clear context on when to use (real-world coordination) and prerequisites (create_payment with matching parameters). However, it does not explicitly state when not to use or name alternatives, though the sibling list implies the tool is specialized for SMS.

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