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

Annotations already cover read-only, idempotent, open-world and non-destructive behavior, so the bar is lower. The description goes further by disclosing that results are ecfr.io mirror links of an unofficial compilation, that text can become stale, and that retrieved text should be treated as data rather than instructions. It does not mention pagination or result-size behavior, but the output-schema exists and limit is bounded.

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 opening sentence is well front-loaded, but the description repeats the same instruction twice ("Fetch matching regulations before quoting" and "Fetch the regulation before quoting a search snippet"), and the citation-formatting rules add bulk. Several sentences could be merged without losing 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?

Given an output schema exists, return values needn't be explained, yet the description still covers return shape (snippets, inline and legal citations, bodyAsOf/sourceDate), sourcing caveats, and quoting obligations. The only gap is the undocumented limit parameter, which is minor for a search tool.

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 description coverage is 0%, so the query and limit parameters are only weakly compensated. The description shows an example query form ("31 CFR 10.1") which clarifies accepted input, but never explains limit, result count, or how many snippets are returned.

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) and resource (current US CFR text), plus the alternative input form (a citation like 31 CFR 10.1). It implicitly distinguishes itself from the siblings get_regulation and list_titles by framing search as the discovery step before fetching.

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?

Explicitly prescribes the workflow: fetch the matching regulation before quoting, never represent stale text as current, include inlineCitation/legalCitation in any regulatory claim, and verify against official sources. It names both the trigger (regulatory claim or quotation) and the constraints, which is exactly the when/when-not guidance expected.

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