list_sms_dids

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

There are no annotations, so the description must carry the behavioral burden. It only notes that data comes from 'SMS Center stats', but it does not disclose whether the operation is read-only, whether results are paginated, what fields are returned, or how the overview is structured.

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 a single sentence with a clear verb-first structure and no filler. The phrase 'DID overview from SMS Center stats' is slightly awkward, but it remains efficient and front-loaded.

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 and no annotations, the description needs to explain what the returned overview includes)Skip this. It does not mention pagination, output fields, or how this differs from list_dids in concrete terms, leaving the agent without enough context for a complete call.

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 tool takes zero parameters and the schema documents this completely, so the description has no parameter meanings to add. The baseline of 4 for a no-parameter tool applies.

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 uses a specific verb ('List') and resource ('SMS-capable DID overview'), and the qualifier 'SMS-capable' helps distinguish it from the sibling list_dids tool. It is clear enough for an agent to know what the tool returns, though 'overview' is somewhat imprecise.

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 given on when to use this tool versus alternatives. The closest sibling, list_dids, is never mentioned, and the description only implies that this variant is for SMS-capable DIDs, leaving the decision to inference.

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