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

Annotations only declare readOnlyHint, so the description carries most of the behavioral burden, and it does add real context: results are newest-first, the response includes a total match count and per-document fields, and calls carry a $0.003 USDC x402 payment. It does not mention rate limits or paging behavior beyond the limit parameter, which keeps it short of a 5.

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 two sentences, front-loaded with purpose and scope before descending into return fields and pricing. The output-field enumeration ('number, title, type, abstract, agencies, publication date...') is somewhat list-heavy but still earns its place given there is no output schema.

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 read-only search over five fully documented parameters with no output schema, this covers most of what an agent needs: query semantics, filter dimensions, sort order, return shape, and payment model. The remaining gap is how limit interacts with result volume and any pagination or rate-limit constraints.

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 all five parameters (q, type, limit, since, agency) are already documented with formats and examples in the schema. The description restates the existence of agency, type and date filters but adds no syntax or semantics beyond what the schema provides, so the baseline 3 applies.

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 verb and resource ('US Federal Register documents ... matching a full-text query') and enumerates the covered document types (final rules, proposed rules, notices, presidential documents). It is clear on its own, but it never contrasts itself with similar search siblings such as clinical_trials_search, papers_search or sec_filings, so an agent gets no explicit routing signal.

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 that a full-text query is the primary path and that agency, type and date are optional narrowing filters. There is no statement of when to prefer this over another search tool, no exclusions, and no guidance on combining a broad query with filters.

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