twilio_send_sms

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

No annotations exist, and the description provides zero behavioral context. It does not mention authentication requirements, rate limits, response format, or any side effects of sending an SMS.

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 extremely short (5 words), which is concise but lacks front-loading of critical context. It is minimal but not structured to aid quick agent understanding.

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 no output schema, no annotations, and 6 parameters, the description is severely incomplete. It omits return value, authentication method, and any operational constraints, leaving the agent to rely solely on parameter names.

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 description adds no meaning beyond the input schema; key parameters like account_sid and auth_token are left undocumented in the description, and the schema's 67% coverage is not compensated.

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 'Send an SMS via Twilio' clearly states the action (send) and resource (SMS) and distinguishes this tool from related siblings like twilio_make_call and twilio_send_verify.

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?

No guidance on when to use this tool versus alternatives. Lacks context for when to choose SMS over calls or verification, and doesn't mention prerequisites or typical use cases.

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