DME denial code explainer (free)

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds value beyond that by enumerating the response payload (title, meaning, common DME causes, fixes, appealability, related codes) and stating the free/no-API-key access constraint, which is real operational context.

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?

Three short sentences with zero waste: purpose first, return payload second, access constraint last. Every sentence earns its place and nothing is buried.

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 one parameter and no output schema, the description correctly compensates by listing the returned fields and noting no auth is required. Minor gap: it doesn't state what happens for an unrecognized code, so behavior on invalid input is unknown.

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% and the single parameter already carries an example set ("CO-50", "PR-1", "197"). The description adds nothing about code format, prefixes, or acceptable variants. Baseline 3 applies when the schema does the heavy lifting.

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: 'Explain a DME claim denial code (CARC)'. That is far more targeted than a generic code lookup and the acronym CARC anchors the domain. It doesn't name or contrast itself with siblings like code_lookup or code_reimbursement, so an agent must infer that this is the denial-specific explainer.

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 implied by the resource itself: this is the tool for denial codes. There is no explicit when-to-use vs when-not, and no reference to alternatives such as code_lookup for non-denial codes. Adequate but leaves routing to inference among 30 siblings.

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