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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered without the description's help. The description adds only that the subject is 'usage statistics' rather than configuration or schema, which is modest value beyond the structured fields.

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?

A single short sentence with no padding, and the key noun ('usage statistics') is front-loaded. It is efficient, though arguably too terse to earn a top score.

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 an output schema present, the description need not explain return values, and the one parameter is fully documented in the schema. The remaining gap is routing: nothing tells the agent why to call this instead of the sibling tools that also operate on a named calculator.

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% and the single parameter carries both a description and a full enum of calculator names, so the schema does the heavy lifting. The description adds no format, default, or naming guidance beyond it, making the baseline 3 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?

States a specific verb ('Get') and resource ('usage statistics') scoped to 'a specific tax calculator', which is more precise than the title. However, it does not differentiate itself from siblings such as get_calculator_schema or list_calculators, which also concern individual calculators.

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 indication of when to reach for this tool versus list_calculators (which enumerates calculators) or get_calculator_schema (which describes their inputs). No prerequisites, no exclusions, no alternative routing is given.

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