Calculate maximum home price you can afford

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

Annotations already mark it read-only and idempotent, and the description adds helpful behavioral context: it performs no network access, duplicates zillow/redfin math, and returns a price, constraint, and PITI breakdown. No contradiction with annotations.

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?

Four tight, information-dense sentences with the core purpose front-loaded. Every sentence adds value—inputs, outputs, equivalence to external tools, and network behavior—with no filler.

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 calculation tool with no output schema, the description covers inputs, algorithm rule, return values, and execution constraints. Minor gaps are the units/formats for interest_rate and property_tax_rate, but the standard-rule framing makes the calculation behavior sufficiently complete.

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?

With 0% schema description coverage, the description compensates by translating most parameters into plain language: monthly income, recurring debts, down payment, interest rate, and optional tax/insurance/HOA/term. It omits explicit mention of the front_end_dti and back_end_dti override parameters, but these are fairly self-explanatory from the 28/36 context.

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 names a specific operation—'Solve for the maximum home price you can afford under the standard 28/36 DTI rule'—with a clear resource and output. It is clear enough to distinguish from most siblings, though it does not explicitly contrast with the sibling compass_calculate_mortgage.

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 implies when to use it: when an affordability figure is needed and when pure local math is preferred ('No network — pure local math'). However, it never names an internal alternative or says when not to use it, leaving the choice vs. compass_calculate_mortgage to inference.

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