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

The readOnlyHint annotation already makes clear this is a safe read operation. The description adds semantic context about what a meter represents, but it does not disclose pagination behavior, authentication scope, return shape, or other operational details beyond the annotation.

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, front-loaded with the purpose, followed by a compact API endpoint reference. There is no wasted language and the structure is easy to scan.

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 tool with fully described parameters and a readOnlyHint annotation, the description is mostly complete. It does not explain the returned meter fields, but no output schema exists and the core purpose is clear.

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 all three parameters are already documented in the input schema. The description adds no parameter-level detail such as how page, limit, or organization_id behave, so the baseline 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 gives a clear verb and resource (list usage meters) and adds useful domain meaning: meters aggregate events into billable quantities. It does not explicitly distinguish this from the related sibling polar_get_meter_quantities, which is the main reason 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?

There is no when-to-use, when-not-to-use, or alternative guidance. The endpoint path is included, but it does not tell an agent whether to choose this over polar_get_meter_quantities or polar_list_events.

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