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

readOnlyHint=true already covers the safety profile, and the description adds genuine context by enumerating the result values (answered, voicemail, busy, no answer) and the 100-per-page behavior. It omits other behavioral facts an agent would want, such as ordering of results, whether results are available before the broadcast finishes, or retention limits.

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?

One sentence, front-loaded with the core action, and the parenthetical status list and page size are the only extras – each earns its place with no filler.

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 full schema coverage, no output schema and no nested objects, this is close to sufficient: the agent knows what it retrieves and the page size. Only minor gaps remain (result availability timing, relationship to sibling get/list tools).

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%, with id, limit and start all documented, including the helpful 'use next_start from the previous reply' note in the schema itself. The description's '100 per page' largely restates the limit default rather than adding new meaning, so the baseline 3 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?

States a specific verb and resource ('List the recipients of a call broadcast') and adds what each row contains ('result per number'), which implicitly separates it from dialmycalls_list_text_recipients. It never names that sibling or dialmycalls_get_call explicitly, so differentiation is implied rather than stated.

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?

Usage is only implied: you call it to inspect per-number delivery outcomes for a broadcast. There is no explicit when-to-use, no note that the id comes from dialmycalls_list_calls or send_call, and no guidance on when to prefer dialmycalls_get_call or dialmycalls_list_text_recipients instead.

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