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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorldHint=false, so the safety profile is covered. The description still adds real value beyond them: inputs are rounded before pricing, ZERO closing costs, a required_disclosure accompanies any rate/APR/payment, disclosures remain in English with a Spanish courtesy translation, and an apply link is returned. This is richer than a 3, so it earns a 4.

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?

Dense but front-loaded: the first sentence pins down what is returned and for which scenarios, followed by two short supporting facts. Slightly overloaded in one sentence, but nearly every clause carries information.

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?

With 11 parameters, 7 required, no output schema, the description compensates by enumerating return fields (rate, APR, points, P&I, closing costs, required_disclosure, apply link) and noting rounding and language behavior. Conditional parameter requirements (balance/cashOut per purpose) are left entirely to the schema, a minor gap rather than a blocker.

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 every parameter (down, balance, cashOut, language, occupancy, etc.) is already documented in the schema. The description only echoes the language=es example, which the schema also covers. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (real CapCenter conventional fixed-rate quotes for 30/20/15-year terms) plus the exact return contents: rate, APR, points, monthly P&I, zero closing costs, required_disclosure, apply link. That level of specificity separates it cleanly from siblings like get_todays_rates and compare_refinance_options.

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?

Gives clear qualifying conditions — a purchase, refinance, or cash-out scenario in a county CapCenter serves, in a state it is licensed in. It never explicitly says when to prefer compare_refinance_options or get_todays_rates instead, so there is no exclusion or alternative routing.

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