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

readOnlyHint already covers the safety profile, and the description adds real behavioral context beyond it: the four passage-selection modes, that citations are resolved from exact title/FR citation/document number found in the text, and that RIN matching is exact. It does not discuss truncation or default result sizing, which the schema only gestures at via the offset parameter.

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 packs in scope, payload, and matching semantics with no filler. It is somewhat run-on with the nested parentheticals, but every clause carries information an agent needs.

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 six-parameter tool with no output schema, the description covers what comes back (status, passages, inbound/outbound citations, same-RIN documents) thoroughly enough to plan a call. The remaining gap is pagination behavior, which is only hinted at through the offset parameter's description.

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 coverage is 100%, so the baseline is 3. The description does add some meaning by tying 'all, one part, one section, or those matching a query' to the parts/section/query trio and explaining that citation matching is exact, but it adds no syntax or format detail beyond the schema's own field descriptions.

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 and access mode ('One Federal Register document by number') and enumerates the payload: status and legal effect, full-text passages, citation graph, and same-RIN documents. It implicitly contrasts with the list/search sibling federal_register by emphasizing 'one ... by number', but never names that sibling, so sibling differentiation is left to inference.

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 can infer this is the tool for a known document number, and the alternative (searching the Federal Register) is suggested by the sibling name rather than the text. There is no explicit when-to-use/when-not statement or prerequisite guidance.

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