bulk_send_sms

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

No annotations exist, so description carries the full burden. It discloses the sync/async behavior and job_uuid for async, but omits side effects like cost, irreversibility, or that it actually sends messages (though 'send' implies this). Adequate but not rich.

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?

Two sentences, zero waste. Action, required fields, either/or condition, and sync/async thresholds are all front-loaded. Every word earns its place.

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 6-param tool with no output schema, it covers the essentials: endpoint, required fields, either/or constraint, and async behavior. It doesn't explain sync output format or error conditions, but the core calling logic is fully described.

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%, so baseline is 3. The description adds a critical constraint not in the schema: the either/or requirement of to[] or list_uuid, clarifying that from+text alone is insufficient. This is valuable beyond the schema.

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?

States a specific verb+resource (bulk-send SMS to many recipients) and includes the HTTP endpoint. Clearly distinguishes from single-send sibling tools like send_sms and schedule_sms by the word 'bulk'.

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?

Gives explicit usage conditions: requires from+text and either to[] or list_uuid, plus sync/async thresholds (≤500 vs 501–50k). Does not explicitly contrast with send_sms for single sends, but the threshold logic provides clear guidance.

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