addBulkCallNumber

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

Beyond the annotations, it discloses meaningful side effects and validation behavior: automatic agent attachment for unassigned numbers, refusal for numbers attached to a different agent, and the not-already-in-pool requirement. This is exactly the behavioral context an agent needs.

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 front-loaded with the action, followed by a pragmatic use context and necessary constraints in a compact, scannable structure. No sentence is wasted.

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 two-parameter mutation with no output schema, the description fully covers operation, when it is useful, prerequisites, side effects, and refusal behavior. The source of phone_number_id is already in the schema, so everything needed to call the tool correctly is present.

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 bulk_call_id and phone_number_id are already documented. The description reinforces that phone_number_id must be one of the user's numbers but adds no new format or source details beyond the schema.

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 opens with a precise verb and resource: 'Add one of your numbers to the campaign's rotation pool.' It clearly scopes the operation to your numbers and distinguishes it from contact-add or generic number-management tools.

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?

It gives a concrete use case—bringing in a fresh number while the campaign is running when the pool lacks healthy numbers—and states eligibility rules. It stops short of naming sibling alternatives or explicit when-not-to-use cases, so not a 5.

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