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

Annotations only declare readOnlyHint=true, and the description adds real context beyond that: returned passages carry citation coordinates (FR page, CFR section/paragraph) and a text-class label, documents carry status and legal effect derived from their own dates, and a coverage signal indicates what has full text. It does not describe ordering or how results are ranked, but the safety profile is already covered by 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?

Four sentences, front-loaded with what is searched and immediately followed by what comes back. Each sentence carries distinct information (scope, citation payload, status/coverage, grounding rule), with only mild density in the citation sentence.

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 8 optional parameters, no output schema, and only a readOnly annotation, the description does the heavy lifting well by describing the shape of returned passages and document metadata. It stops short of explaining result ordering, pagination beyond the 'limit' parameter, or what the coverage signal contains.

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, but the description genuinely enriches two parameters: it explains the meaning of 'parts' by naming the text classes (rule text, proposed text, presidential text, agency explanation) and explains that 'status' reflects legal effect computed from document dates. It adds nothing about date or agency filter behavior, which the schema already covers.

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 verb (search) over a specific resource (Federal Register documents and the passages of their full text), and enumerates the document classes covered. This clearly separates it from the sibling federal_register_document, which by name retrieves a single document rather than searching across documents and passages.

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 gives clear context for when to reach for this tool: keyword search across documents and their text, with the 'parts' dimension for narrowing to operative vs. explanatory text. It adds a strong usage constraint ('Say what a document requires, authorizes or prohibits only from the passages returned'), but never names an alternative sibling or an explicit when-not condition.

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