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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so the safety bar is met. The description adds substantive content disclosure — that the response contains a filter definition, a server-side vs local filtering split, vintage and retrieval date, covered states, and limitations — which tells the agent what it will actually receive beyond the annotation profile.

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?

A single front-loaded sentence that announces the topic and then enumerates the returned components with no filler. It is dense but every clause maps to a distinct piece of content.

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 reference tool with no output schema, the description enumerates the returned content well enough that an agent knows what to expect. It could be marginally stronger by noting the tool returns no query parameters or that it is a static reference, but nothing essential for correct invocation 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?

The schema is an empty object with zero parameters, so there are no parameter semantics to convey; per the 0-param baseline this scores 4. The description correctly avoids inventing arguments.

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, non-tautological purpose: it returns the build methodology behind the investor-lender data, enumerated as filter definition, filtering split, vintage/retrieval date, covered states and limitations. An agent can tell this is the reference/lineage tool rather than a data-returning sibling like investor_lenders_aggregate or investor_lenders_by_state, though no sibling is named explicitly.

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 closing clause ('the stated limitations an agent should attach to any figure it reports') gives actionable context for when to consult it — alongside reporting of any figure. It stops short of explicitly contrasting with the sibling data tools or stating prerequisites, but the usage context is clear rather than merely implied.

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