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

Annotations already establish readOnly, idempotent, non-destructive behavior. The description adds valuable behavioral context by revealing default status filtering, chronological ordering, and the exact row fields (send_at, status, attempts, Twilio sid, last error). No contradiction with annotations exists.

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 two tight sentences with no filler. The most important operational detail (default statuses and ordering) is front-loaded, and the output fields are listed compactly in the second sentence.

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 simple read-only list tool with one optional parameter and no output schema, this description is complete: it covers the default behavior, how to access history, ordering, and the relevant fields in each row. Nothing essential is missing for correct invocation.

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 schema already documents the status parameter with 100% coverage, but the description adds meaning beyond it by explaining that status=sent|failed|cancelled reveals history and by clarifying the default behavior of pending + sending. This helps an agent choose the right parameter value without needing to infer semantics from the enum alone.

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 and resource ('List your org's scheduled texts') and clearly differentiates this from siblings like tascan_schedule_sms, tascan_send_sms, tascan_get_sms_status, and tascan_cancel_scheduled_sms. It also conveys the default scope and the kind of data returned, leaving no ambiguity about what this tool does.

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 on when to use the default view versus when to pass status=sent|failed|cancelled to see history. It does not explicitly name alternative tools or state when not to use this tool, but the guidance is sufficient for a simple read-only list operation.

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