List Broadcast Recipients

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

Annotations already mark this as read-only, and the description adds useful behavioral detail beyond that: it returns per-recipient rows, one per contact per event type, includes event-specific fields like bounce_type and clicked_links, and explains pagination via limit/after/before. No contradiction with the readOnlyHint.

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 longer than minimal but every section serves a purpose: purpose, exclusions, return semantics, and usage triggers. It is well-structured and front-loaded, though some of the example phrasings in 'When to use' are slightly redundant with the earlier 'NOT for' section.

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?

Even though there is no output schema, the description explains the return shape sufficiently: per-recipient rows, key fields, event-specific extras, and pagination. It covers the practical workflow of resolving a broadcast ID. It could have noted error conditions or rate limits, but these are not essential for 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 coverage is 100%, so the baseline is 3, but the description enriches the 'type' parameter by explaining what fields come back for opened/clicked/bounced, and it clarifies pagination semantics for limit/after/before. It adds practical meaning beyond the schema's field-level descriptions.

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 states a specific verb and resource: 'List the individual recipients of a broadcast for a given event type.' It clearly enumerates the event types and distinguishes itself from get-broadcast and list-broadcasts, so an agent can immediately tell what this tool does.

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 explicitly says what this tool is NOT for and names the alternatives: aggregate performance should use get-broadcast, and listing broadcasts should use list-broadcasts. It also gives concrete user-intent examples ('who opened this broadcast?', 'who bounced?') and advises using get-broadcast first to resolve a broadcast name to an ID.

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