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

The description adds valuable behavioral context by disclosing that the tool is paid via x402 / X-Bazaar-Key at 0.01 USDC, which is not captured in annotations. It does not explain the return format or the handling of missing margin input, but the payment requirement is a key disclosure.

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 a single, front-loaded sentence that efficiently conveys the purpose and payment requirement without wasted words. It could be slightly better structured to separately address inputs and outputs, but it remains appropriately concise.

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 calculator with no output schema, the description should explain the return value and how to supply the mentioned margin percentage, but it does neither. The payment note and core purpose are present, yet critical details for correct invocation are 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 coverage is 100% for the single documented parameter (yoy_arr_growth_pct), so the baseline is 3. The description mentions a second input (FCF/EBITDA margin percentage) that is not present in the schema, creating a semantic mismatch that the description does not clarify.

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 states a specific verb (Compute) and resource (SaaS Rule of 40 score), making the tool's purpose immediately clear. However, it does not explicitly differentiate itself from related sibling tools like suite_saas_cfo_scorecard, 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 description offers no explicit guidance on when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites beyond the payment requirement. Usage is only implied by the tool's name and purpose.

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