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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the description is not required to restate safety. The description adds useful context: the active-company scope and that CRM account IDs are included for campaign exclusions, but it does not disclose operational behaviors like pagination defaults beyond schema-provided parameter limits.

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 a single sentence with no redundant words. It front-loads the core function and includes the two most decision-relevant details: active-company scoping and the special CRM account ID return field.

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 simple read-only list operation with a rich input schema, a true output schema, and safety annotations, the description provides enough context to invoke the tool correctly. It could briefly mention that filtering by statuses and pagination are available, but those are already fully documented in the schema.

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 the schema documents eventId, limit, offset, and statuses with type, range, and enum information. The description adds no parameter-level semantics beyond the mention of registrations, which does not change the baseline score for fully covered parameters.

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 uses a specific verb and object ('List registrations for an event') and adds the active-company scope plus the distinctive CRM account IDs output. It is unambiguous, but it does not explicitly differentiate from sibling tools such as get_event_campaign_exclusions, which is related to campaign exclusions.

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 clearly communicates the intended use case: retrieving an event's registrations in the current company. It does not state explicit when-not-to-use conditions or name an alternative, but the purpose is sufficiently contextual for an agent to select it over unrelated list tools.

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