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

Annotations already cover the safety profile (readOnly, non-destructive), and the description adds what they cannot: the required role/permission and the 31-day window limit that will actually cause calls to fail. It omits anything about result ordering or what happens if all filters are omitted, which keeps it off a 5.

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?

Three short sentences, front-loaded with what is returned, then the period constraint, then the permission requirement. Nothing is padded and no sentence restates another.

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 no output schema, the description does explain the returned fields (member, event, amount paid), and the schema covers limit/truncation messaging. The remaining gap is small: no statement of default ordering or what an unfiltered call returns.

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 each parameter is already documented, setting the baseline at 3. The description adds only the shared 31-day cap on the from/to date pairs and confirms the two boolean includes are optional enrichments; it does not clarify date formats or what happens when both period families are supplied.

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?

States a specific verb and resource ('Active registrations for events, clinics and lessons') plus the payload contents (member, event, what was paid). The word 'Active' alone distinguishes it from the sibling courtreserve_list_cancelled_event_registrations, and 'event registrations' separates it from the reservation/check-in list siblings.

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?

Gives real preconditions and constraints: the required EventRegistrationReport (Read) role and the rule that each period must span at most 31 days. It does not explicitly say when to pick this over the cancelled-registrations sibling, so it stops short of full routing guidance.

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