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

Annotations already declare read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds genuine semantic context beyond that: that listed assignment is not proof of success or coverage, and that forwarding is an optional route. It does not mention pagination or result size.

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 purpose and the empty-data caveat are front-loaded, and most sentences earn their place. The trailing sentence about forwarding being an optional route is somewhat tangential to selecting or invoking the tool.

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?

With an output schema present, return values need not be described, and annotations cover the safety profile. The description supplies the caveat about assignment not proving readiness, which is what an agent most needs here; only pagination/limit behavior is unaddressed.

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% for the single business_id parameter, so the schema already documents it fully. The description's phrase 'accessible business(es)' aligns with that filter but adds no syntax or format detail beyond the schema, making the baseline 3 appropriate.

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 phone numbers), the scope (assigned to accessible businesses), and what is returned (capability and compliance flags). It also differentiates from the sibling get_activation_status, so an agent can distinguish it without opening the schema.

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?

Explicitly routes the agent to get_activation_status for readiness and private-test proof, and clarifies that assignment does not imply successful inbound testing or coverage. It gives clear context and one named alternative, though it stops short of enumerating all when-not conditions.

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