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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds meaningful operational detail beyond annotations: cancelled registrations are omitted and unmatched guests cause the readiness flag to be false, which is useful behavioral context.

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?

Two sentences with no filler. The first states the core purpose and output; the second adds the critical usage constraint and edge-case behavior. Information is front-loaded and every sentence earns its place.

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 single-parameter, read-only tool with an output schema, the description provides the essential operational guidance: what event is targeted, what the IDs are for, and when the result should be trusted. The 'ready=true' caveat is especially important 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 description coverage is 100% for the only parameter, eventId, which is described as 'Event ID'. The description does not add further detail about the eventId parameter, so the schema carries the meaning and the baseline score of 3 is 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?

The description states a specific operation ('Resolve pending, confirmed, and paid event registrations into unique CRM account IDs') and a clear purpose ('for campaign exclusions'). This differentiates it from sibling raw-registration tools by emphasizing the transformed output and exclusion context.

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 explicitly instructs when the result should be consumed ('Pass accountIds to audienceExclusions only when ready=true'), and clarifies which registrations are omitted. It does not name an alternative tool or state when not to use it, but the usage context is clear.

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