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

Annotations already cover the read-only, non-destructive profile. The description adds meaningful behavioral calibration beyond that: outputs are described as typical and general ('typically appealable', 'general appeal path'), and the 'Not legal advice' caveat signals heuristic, non-authoritative results. This is useful context an agent needs before relying on the answer.

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?

Two sentences with zero filler: the substantive explanation is front-loaded and the legal disclaimer is cleanly separated. Every clause earns its place, and the sentence-splitting improves scannability.

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?

For a single-parameter, read-only informational tool with a fully documented schema, the description conveys the output shape (meaning, appealability, appeal path) even without an output schema. Minor gaps remain: no statement about invalid/unknown code handling, and the description says CARC while the schema also accepts RARC codes, a slight narrowing.

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 schema already documents the parameter well, including format examples ('CO-16', '16', 'CO-50') and the note that RARC codes are accepted. The description only reinforces the CARC/X12 framing and adds no format or syntax detail beyond the schema. Baseline 3 applies because the schema carries the semantic weight.

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 ('Explains') and a precise resource ('CARC claim-adjustment reason code from the public X12 code list'), and enumerates the three output aspects: meaning, typical appealability, and general appeal path. This scoping differentiates it from siblings like lookup_procedure_code (procedure codes) and get_appeal_deadline (deadlines, not the appeal path).

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 scope implies the trigger condition: an agent holding a CARC code who needs its meaning or appealability would select this tool. However, the description gives no explicit when-to-use or when-not-to-use guidance and does not name alternatives, despite some overlap in territory with get_appeal_deadline and lookup_procedure_code.

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