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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds behavioral detail beyond annotations: it restricts to already-published final rules (not proposed), orders by effective date soonest first, and specifies returned fields including a verbatim quote. No auth or rate-limit details are added, but the read-only nature is already annotated.

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 description is compact and front-loaded with the essential scope ('Lists already-published US federal final rules'), then gives ordering, optional filter, output details, and closes with a usage pointer. Every sentence earns its place; no filler.

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 the output schema present, the description covers the key behavioral aspects an agent needs: scope (final rules), date range semantics, ordering, optional agency filter, and the specific fields returned. It also warns against misuse (not topic search). This is complete for a read-only list tool with well-documented parameters.

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 100%, so the schema fully documents all four parameters including formats, defaults, and matching behavior. The description adds minimal parameter information: it mentions the date range and optional agency filter, but these are already clear from the schema. Thus the baseline 3 is appropriate.

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?

Description states a specific verb and resource: lists already-published US federal final rules by effective date range. It also explicitly distinguishes itself from topic search and frames the compliance-calendar use case, making it easy to differentiate from siblings like list_rules_amending_cfr_part.

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 includes an explicit use case ('what takes effect in Q4') and an exclusion ('not for searching the Federal Register by topic'), but does not name a specific alternative tool for topic search or CFR-part queries. The schema does point to list_agencies for agency names, but the main description lacks the explicit sibling comparison that would earn a 5.

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