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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false. The description adds useful behavioral context by stating the calculation is deterministic, uses exact integer USD cents, and returns structuredContent fields including statelessEphemeralAudit and calculation.

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 front-loaded with the core calculation and plan-fit purpose, then covers inputs and return fields in three efficient sentences. The output field list is justified because no output schema exists.

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?

The input schema is fully described, annotations cover safety and idempotency, and because there is no output schema the description usefully enumerates the key returned structuredContent fields. Nothing essential for correct invocation appears missing.

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 already documents ranges, defaults, and tier thresholds for all four parameters. The description repeats the parameter names and their role in recommending a tier, but adds no parameter semantics beyond what the schema provides.

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 specific verb and resource: calculate monthly and annual B2B margin savings and recommend the optimal RevClamp plan tier. It distinguishes the tool from sibling audit/evaluate tools by focusing on ROI calculation and plan fit rather than leakage auditing or usage evaluation.

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 provides a clear usage context: replacing a 25%-30% contingency chargeback agency with RevClamp flat-rate plans. It does not explicitly name when-not to use it or name sibling alternatives, so it falls short of a 5.

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