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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is well covered. The description adds the source, per-call price, and GET method, which are consistent with the annotations. However, it does not disclose the return format or clarify that the date parameter can select a historical effective date, despite the word 'current.'

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 a single efficient sentence followed by three short metadata fragments. Every clause adds value: what it does, the source, the cost, and the endpoint. The 'CFR legal text:' prefix is slightly redundant with the title but does not detract from clarity.

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's statement that it returns 'text' is helpful, and the schema fully documents the four flat parameters. However, the description does not clarify how a CFR citation is constructed (which combinations of title, part, and section are valid) even though only title is required. This leaves an agent uncertain whether a title alone is sufficient and whether part/section are additive filters.

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%, with each parameter having a description and examples, so the schema carries the parameter documentation burden. The description adds only the vague notion of 'a citation' without explaining how title, part, and section combine. Therefore, the baseline score of 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?

The description states a specific action and resource: 'Fetch current Code of Federal Regulations text for a citation.' It also names the source (eCFR/GovInfo), making the tool's scope immediately identifiable. Among the sibling tools, none covers CFR legal text, so it is readily distinguished without requiring schema inspection.

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 clearly frames the use case: retrieving current CFR text for a citation. It adds useful context by specifying the source, cost, and HTTP method. It does not explicitly list when-not-to-use alternatives, but because no sibling tool competes for this exact resource, this is a minor gap.

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