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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the useful economic assumption behind the calculation, but says nothing about what the result contains (profit give-away figure, breakdown, units) or how discount/term inputs are compounded, which a pure-computation tool should disclose.

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 first sentence is dense and front-loaded, but the second is a promotional external URL that does not help the agent invoke the tool. Roughly half the description is non-actionable for a tool call.

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?

All required inputs are covered by the schema and the operation is read-only per annotations, but with no output schema the description should describe the returned figure (e.g., lifetime profit forgone). That gap leaves the agent unsure what the computation yields.

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 all four parameters (listAcv, discountPct, termYears, grossMarginPct) are documented in the schema. The description adds no syntax, unit, or range information beyond that, so baseline 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?

States a specific verb ('show how much lifetime profit... gives away') on a specific resource (enterprise contract discount), and adds a modeling assumption (cost-to-serve doesn't drop with price) that clarifies what is being measured. It does not explicitly distinguish itself from near-neighbors like gross_margin_impact_calculator or pricing_elasticity_sandbox, which keeps it out of 5 territory.

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 scenario (evaluating an enterprise discount offer) is implied by the framing, but there is no explicit when-to-use, when-not-to-use, or named alternative. With many overlapping pricing/margin siblings, the agent gets no routing guidance.

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