send_sms

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

With no annotations provided, the description carries full burden but offers minimal behavioral disclosure. It states the action is to 'Send SMS message' which implies a write operation, but doesn't cover permissions, rate limits, delivery confirmation, costs, or error handling. For a mutation tool with zero annotation coverage, this is inadequate.

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 concise - just four words - and front-loads the core action. Every word earns its place with no redundancy or unnecessary elaboration.

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 mutation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what happens after sending (success/failure indicators), doesn't mention authentication requirements, and provides no context about the assistant integration. The 100% schema coverage helps with parameters but doesn't compensate for the lack of behavioral context.

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 all parameters are documented in the schema. The description doesn't add any meaningful parameter context beyond what's already in the schema descriptions (e.g., it doesn't explain format requirements for phone_number or message length limits). Baseline 3 is appropriate when schema does the heavy lifting.

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 action ('Send SMS message') and specifies the mechanism ('through assistant'), which distinguishes it from other communication tools like make_call. However, it doesn't explicitly differentiate from all sibling tools that might involve messaging or assistant interactions.

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 is provided on when to use this tool versus alternatives like make_call or chat_with_assistant. The description mentions 'through assistant' but doesn't explain prerequisites, constraints, or appropriate contexts for SMS versus other communication methods.

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