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

Annotations already cover read-only, idempotent, non-destructive, and closed-world behavior, so the description adds useful context beyond them: required authorization scope, pagination behavior, returned counts and next cursor, and explicit negative capabilities. This gives the agent a clear operational picture.

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 core action and scope, then adds return fields, authorization, and exclusions in three efficient sentences. There is no filler, and each sentence contributes relevant information.

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 annotations covering safety and an output schema available, the description is largely complete for a read-list tool: it covers scope, auth, pagination, and side-effect exclusions. The remaining gaps are explicit sibling routing and fuller parameter semantics, but neither prevents correct 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?

Schema description coverage is 0%, so the description must compensate. It does identify that `id` is a campaign id and that `limit` and `cursor` drive pagination, but it does not explain `limit`'s default/range or the cursor token's origin/format, leaving those details to the schema constraints.

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 first sentence gives a specific verb and resource: list authorized recipient records for a campaign id with pagination. It is clearly not a get-one or mutation tool, but it does not explicitly name the sibling `recipients_get` or otherwise differentiate from it beyond the list/get naming convention.

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 provides clear context: use it for recipient records for a supplied campaign id, with required `recipients:read` scope, and it explicitly excludes editing contacts, generating videos, and sending messages. However, it does not name alternatives such as `recipients_get` or state when to prefer one over the other.

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