get_mortgage_summary

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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds valuable context by enumerating the return fields (origination count, denial rate, etc.) and citing the data source (CFPB/FFIEC HMDA). This gives the agent a clear picture of what the tool provides beyond the schema.

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: the first states the action and scope, the second lists outputs. No wasted words, front-loaded with the primary purpose. This is exemplary conciseness.

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?

Given no output schema, the description explains return values in detail, listing six specific metrics. It covers the source and geographic scope. It does not discuss error cases or data coverage gaps, but for a read-only summary tool with good annotations, this is adequate.

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?

The input schema has 100% coverage, with descriptions for year, geoid, and area_type. The description adds no additional parameter semantics beyond saying 'census tract, county, or state,' which aligns with the area_type enum. Baseline 3 is appropriate because the schema carries the parameter documentation weight.

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 the tool's purpose: 'Retrieve the mortgage lending summary for a single geographic area (census tract, county, or state) from HMDA data.' It identifies the specific resource (mortgage lending summary), scope (single area), and data source. This differentiates it from sibling tools like get_mortgage_trends and compare_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 usage for a single-area summary but does not explicitly specify when to use this tool over alternatives like mortgage trends or compare tools. It lacks explicit guidance such as 'for historical trends, use get_mortgage_trends.' The mention of 'single geographic area' is useful but not a complete usage guideline.

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