spix_sms_list

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

No annotations are provided, and the description simply repeats the name. It fails to disclose behavioral traits like read-only nature, pagination, or sorting. For a tool with zero annotation coverage, the description carries full burden and does not fulfill it.

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 (4 words) but lacks substance; it is essentially a tautology. While front-loaded, it does not convey necessary information, making it under-specified rather than concise.

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?

With 4 parameters, no output schema, and no annotations, the description is grossly incomplete. It omits pagination behavior, output format, and any usage nuances, making it inadequate for an AI agent to use correctly.

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%, and each parameter has a description. The tool description does not add value beyond the schema, so baseline 3 is appropriate.

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 'List SMS messages' clearly states the verb (List) and resource (SMS messages), distinguishing it from siblings like spix_sms_send or spix_sms_thread. However, it lacks explicit differentiation or further context, so it's not a 5.

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 such as spix_sms_thread or other list tools (e.g., spix_call_list). The description provides no context, exclusions, or examples.

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