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

Annotations already cover read-only, idempotent, non-destructive safety, so the description correctly spends its words on methodology instead. It discloses the day-count conventions (21 business days/month, 252/year, 4.33 weeks/month) and the present-value discounting approach for APR, which materially affect results and are not in the schema. Minor gap: no note on rounding or how partial payment counts are handled.

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 conversion and its outputs, followed by the calculation conventions that justify the results. Nothing is redundant, though the 'same formula as the FundingTracker MCA calculator' clause is the weakest use of space.

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?

An output schema exists and annotations carry the safety profile, so the description needs only to establish the conversion and its conventions — both done. The day-count and APR discounting disclosure is exactly the information an agent needs to trust and interpret the numbers.

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%, with bounds, examples and the factor-rate-to-payback relationship already documented per parameter. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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 and resource ('Convert a merchant cash advance factor rate') and enumerates the exact outputs: total payback, cost of capital, payment size, number of payments, effective APR. This clearly separates it from siblings like estimate_mca_payoff and mca_payment_impact.

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?

Usage is only implied by the mention of the 'FundingTracker MCA calculator' formula, giving some context for when this tool is the authoritative source. However, there is no explicit when-to-use versus estimate_mca_payoff or mca_payment_impact, and no stated exclusions or prerequisites.

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