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

Annotations already declare readOnly, idempotent, non-destructive, and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the substantive content of the response — including that the funding lender makes the credit decision and that owner-occupied lending is excluded — which is behavioral context an agent should not misattribute. It does not state that the answer is static/no-parameter, a minor omission given the empty 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?

One sentence, front-loaded with 'The entity answer:' followed by a tight list of returned fields. No filler or marketing language. The long parenthetical about the business model is dense but carries genuine content rather than padding.

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 and no parameters, the description effectively serves as the output contract by enumerating the exact fields returned, including the founder's canonical Person @id. For a zero-argument static lookup, nothing an agent needs in order to call it and interpret the result 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 tool takes zero parameters, so the baseline is 4. The description correctly makes no parameter claims and instead spends its words on what the parameterless call returns.

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 — 'the entity answer' about the lending provider — and enumerates exactly what it covers: legal name, business model, scope, address, phone, state coverage, founder @id. An agent can tell this is the identity/profile lookup rather than a data-series tool like investor_lenders_aggregate or rate_ranges. It stops short of naming a sibling to contrast against, which keeps it at 4 rather than 5.

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?

Usage is only implied: an agent infers this is the tool for 'who is this company / what do they do / where are they' questions. There is no explicit when-to-use statement, no exclusion (e.g. 'do not use for program terms — see loan_programs'), and no note that a single call answers all identity questions at once. Adequate but with a clear gap.

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