list_sms_chats

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

No annotations are provided, so the description carries the full burden. It discloses important behavioral traits: the user parameter can accept display or login names and is resolved automatically, the contact parameter must be an internal ID (not a person's name), and the sort field has a warning against using invalid fields like 'created' or 'edited'. This goes beyond a simple 'list' statement, though it doesn't mention auth, rate limits, or error cases.

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 well-structured with a one-sentence overview followed by a clear Args list. It is detailed but not verbose; every line provides necessary information for correct usage. The warning about sort fields is important and earns its place, and the parameter explanations are compact yet complete.

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 10 parameters, no annotations, and an output schema (which handles return value documentation), the description covers all parameter semantics and key behavioral nuances. It provides actionable instructions for filters, pagination, and sorting. The only minor omission is explicit mention of auth or rate limits, but for a listing tool this is not critical.

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 0%, so the description must compensate, and it does so excellently. Every one of the 10 parameters receives a clear explanation, including formats, examples, defaults, and direct guidance (e.g., direction must be 'IN' or 'OUT', date formats are YYYY-MM-DD, sort_dir default is 'desc'). The descriptions add significant meaning beyond the schema's bare types and defaults.

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 starts with 'List SMS activities with SMS-specific fields', clearly specifying the action (List), the resource (SMS activities), and the distinguishing detail (SMS-specific fields). This separates it from sibling tools like list_emails or list_web_chats.

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 that this tool is for listing SMS activities and includes helpful parameter guidance, such as using list_queues to find queue names and list_contacts to find contact IDs. It doesn't explicitly state when not to use this tool or name alternatives, but the focus on SMS-specific fields implies when it is appropriate.

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