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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is covered. The description adds genuinely new context: the data source (CFPB HMDA 2025, actions 1,2,3; loan_type 2), the nature of the result (historical observation, not a prediction about an individual application), and the national benchmark (22.1 percent). It does not discuss caching or return shape in more detail, but the added provenance goes well beyond the 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?

The description is dense but deliberately structured with ANSWERS / PARAM / NOT FOR labels, front-loading the question forms before constraints. Every clause adds routing, parameter, provenance, or disclaimer value, though the attribution and provenance sentences could be trimmed slightly.

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 no output schema, the description still characterizes the return ('state 2025 rate and counts against the national 22.1 percent'), plus provenance, scope limits, alternatives, and a misuse disclaimer. Nothing an agent needs to call this single-parameter read correctly is missing.

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 0% and the only schema constraint is min/maxLength 2, so the description carries the full burden: 'two-letter USPS code only (OH, TX); full names are rejected.' That states both the accepted format and the failure mode, which the schema alone cannot convey.

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 resource (state-level FHA denial rate for 2025) and frames it as answering concrete questions, e.g. 'what is the FHA denial rate in <state>'. It also explicitly carves itself out from siblings covering metro/city (get_metro_lender_gap) and lender-level questions, so an agent can pick it without opening another schema.

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?

It gives explicit when-to-use triggers via the 'ANSWERS:' question list and explicit when-not-to-use with named alternatives ('NOT FOR: metro or city questions (use get_metro_lender_gap) or lender-level questions'). Nothing about routing is left to inference.

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