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

Beyond the readOnlyHint and destructiveHint annotations, the description discloses that the tool uses deterministic math, does not quote lender terms, and returns which constraint binds. This is meaningful behavioral context that helps the agent set expectations without calling the tool.

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 focused sentences with no filler. The action, resource, calculation method, output, and an important exclusion are all packed efficiently, with the key result stated early.

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 tool with nested optional thresholds and no output schema, the description covers the main return contract and calculation scope well. It could note threshold defaults or the exact output shape, but the required inputs and core behavior are clear enough for correct invocation.

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 75% and the description adds value by explaining the four constraint categories that drive the calculation, which helps map the threshold fields like maxLtv, minDscr, and minDebtYield to their real-world meaning. It does not explain defaults or exact parameter relationships, but it goes beyond the raw schema.

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 clearly states a specific verb and resource: size a commercial real estate loan. It further specifies the unique output — maximum supportable loan as the minimum of LTV, DSCR, debt yield, and LTC — which distinguishes it from sibling tools like calculate_payment or compare_loan_offers.

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 gives clear context: use this tool when you need a first-principles, deterministic loan sizing calculation. It also gives an explicit exclusion by noting it does not quote lender terms, though it does not name sibling alternatives directly.

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