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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds that these are raw ingested events for metering (useful distinction from aggregated/quantities data), but says nothing about pagination defaults, ordering, or volume/rate constraints for what could be a high-cardinality event stream.

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 compact sentences with the purpose front-loaded and no padding. The trailing 'Polar: GET /v1/events/' is endpoint metadata of marginal value to an agent, which keeps it out of 5 territory.

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 read-only list tool with all 8 params fully described in the schema and a readOnlyHint annotation, the description covers enough to invoke it correctly. With no output schema, however, it gives no hint about the shape of an event record or pagination metadata, leaving a real gap for an agent interpreting results.

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 every one of the 8 parameters (name, page, limit, meter_id, customer_id, timestamps, organization_id) is already documented. The description's filter summary adds no syntax, format, or defaulting detail beyond the schema, so the baseline 3 applies.

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 ('List the raw usage events ingested for metering') and adds the filterable dimensions. It implicitly separates itself from polar_list_meters (meter definitions) by calling these 'raw usage events', but never names a sibling explicitly, so it falls short of a 5.

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 filter list ('customer, meter, name or time') implies when the tool is useful, and the read-only list framing makes intent clear, but there is no explicit when-to-use, when-not-to-use, or pointer to an alternative tool such as polar_get_meter_quantities or polar_list_meters.

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