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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety bar is low. The description adds real behavioral context: the text is fetched live from the eCFR, and results carry citation and URL. It does not mention fetch failures, rate limits, or what happens if a paragraph citation is invalid, which keeps it below 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?

Front-loaded with the purpose and usage rule in the first two sentences, then a dense but justified enumeration of ten sections. There is mild redundancy: the CFR section numbers are listed twice, once in the opening sentence and again in the per-section breakdown.

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, the description correctly notes that citation and URL are returned, and it fully maps what each of the ten enum values will yield, which is what an agent needs to pick a section. It omits failure modes such as invalid or malformed paragraph citations on a live fetch, leaving a minor gap.

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 meaningfully enriches the section enum by describing what each value contains (e.g. 1.45-8 covers labor hours (b), ratio (c), participation (d); 541.101 covers the 20% owner exemption). The paragraph guidance (shorthand g7, omit for whole section) largely restates the schema, so it lands at 4 rather than 5.

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 and resource: returns the current text of a regulation paragraph live from the eCFR, with citation and URL. The named sections (26 CFR 1.45-6 through 48E-3, plus 29 CFR 541.101/5.5/5.31/29.5) make the scope unambiguous and distinguish it from the check_*/count_* siblings that compute rather than read.

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?

Gives concrete usage context: pass a paragraph like '(d)' or '(g)(7)' to read one part, omit it for the whole section. The 'live, eCFR' framing implies when to reach for authoritative source text versus derived tools, but it never explicitly names an alternative (e.g. pwa_overview or official_sources) or states when NOT to use it.

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