list_calls

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

Without annotations, the description carries the full burden. It states 'List phone calls', implying a read-only operation, but does not explicitly confirm non-destructiveness, permissions required, or any potential side effects. The brief description does not add behavioral context beyond the obvious.

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 very concise (one sentence) and front-loaded with the primary purpose. It avoids unnecessary verbosity. However, it could be slightly more informative without becoming too long, such as mentioning pagination or the response structure.

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 4 parameters and an output schema, the description is too sparse. It fails to cover pagination, sorting, or any other common query parameters. While the output schema may document the return structure, the description should at least hint at the result format or field count. It is incomplete for an effective agent 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?

With 0% schema description coverage, the description adds only limited meaning: it mentions date range filtering, which partially explains created_on_or_after and created_on_or_before. However, page and page_size parameters are completely undocumented, and the description does not specify the expected date format or that it is YYYY-MM-DD.

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 clearly states the verb 'List' and the resource 'phone calls', and adds a specific filtering capability by date range. However, it does not define what constitutes a phone call (e.g., inbound vs outbound, from a specific system), and it fails to differentiate from other list_* sibling tools beyond the entity name.

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 no guidance on when to use this tool versus alternatives. Sibling tools include many list_* endpoints for different entities, but there is no mention of prerequisites, exclusions, or when another tool might be more appropriate (e.g., a search_calls tool does not exist in siblings).

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