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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: results are paginated, and it enumerates what each record contains (ids, PSTN destination, capacity limit, priority, group id, assigned DID count, creation time).

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 dense but front-loaded sentence that puts the resource and scope first and the filtering conditions second. No filler, though the trailing enumeration of return fields is long and could be trimmed.

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?

No output schema exists, and the description compensates by listing the returned fields and noting pagination, so an agent knows what it will get back. Combined with the annotations covering the safety profile and the fully documented schema, nothing needed to call this tool is missing.

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%, so both the name and type semantics ('case-insensitive, partial match' and the enum filter) are already documented. The description restates the same filtering semantics without adding format details, defaults, or interactions, so 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 authenticated customer's Voice IN Trunks (inbound voice trunks)') and clarifies the domain term with a parenthetical. It does not name or differentiate from nearby siblings such as list_sms_trunks, list_trunk_groups, or get_trunk, so the agent must infer separation from the name alone.

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 implied: list trunks, optionally narrowed by name or type. There is no explicit when-to-use statement and no routing to alternatives — notably nothing tells the agent to use get_trunk for a single trunk or list_sms_trunks for the SMS variant. Adequate but leaves selection to inference.

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