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

The readOnlyHint annotation already establishes that this is a safe read operation, so the description's main job is to add context beyond that. It does not describe the return structure, pagination behavior, authorization needs, or any listing constraints, leaving behavioral details almost entirely to structured fields.

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 a single front-loaded sentence with no filler, which is appropriate for a simple list tool. The trailing domain phrase is slightly ambiguous but does not significantly harm 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?

For a low-complexity read-only list tool with fully documented parameters, the description is minimally adequate. However, with no output schema and no mention of pagination or return shape, it leaves some context an agent might want before invoking the tool.

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 100%, and both parameters include clear inline documentation for the cursor and page size. The description adds no additional parameter meaning beyond what the schema already provides, which matches the baseline for fully documented schemas.

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 clear verb, 'List', and a specific resource, 'SIP trunks', so the agent can identify the operation. It does not explicitly distinguish the tool from the sibling 'spokephone_get_trunk', and the qualifying phrase about overlaying a legacy PBX adds domain flavor but not operational differentiation.

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 gives no guidance on when to use this tool instead of related tools such as spokephone_get_trunk or the other list endpoints. It also does not mention pagination usage, even though the schema exposes cursor and page-size parameters.

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