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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered without description helping. The description adds significant value by enumerating exactly what information the tool discloses (filter definition, server-side vs local filtering split, vintage, retrieval date, covered states, limitations), giving the agent a clear picture of the response content.

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 definition is a single, front-loaded sentence that immediately says what the tool provides and then lists its components. There is no filler or redundant text.

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 zero-parameter, read-only informational tool with no output schema, the description effectively serves as an output preview by enumerating all the methodology components an agent would receive. Nothing required to call or understand the tool 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?

There are zero parameters, so the baseline score of 4 applies. The schema description coverage is 100%, but no parameter semantics exist to document.

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 states a specific resource and its scope: it returns the methodology for how investor-lender HMDA data is built, listing the exact components (filter definition, filtering split, vintage, covered states, limitations). This clearly distinguishes it from sibling tools like investor_lenders_aggregate and investor_lenders_by_state, which return figures rather than methodology.

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 by noting that the stated limitations should be attached to any figure the agent reports, but it does not explicitly say when to call this tool versus alternatives such as about_national_loan_provider or glossary_lookup. The guidance is inferable rather than directly stated.

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