Medicare DMEPOS prior-auth required check (free)

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

Annotations already cover readOnly/idempotent/non-destructive, and the description adds substantial context on top: no API key needed, no cost, the null-return behavior for state-phased items, and the FFS-only scope that excludes Medicare Advantage. This tells the agent exactly what it will and will not get back before calling.

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?

Four tight sentences, front-loaded with the core check and followed by return values, the state caveat, and scope. No repetition of the title or 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 no output schema, the description carries the return-value burden and does it: paRequired flag, category, nationwide-since date, and list version are all enumerated. Combined with the null caveat and scope limit, an agent has everything needed to call and interpret the result.

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 adds the consequence the schema omits: omitting state yields paRequired = null for phased-in items rather than a wrong answer. That is meaningful semantics beyond the enum list and the 'default today' note.

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: checks whether a HCPCS code appears on the current CMS Required Prior Authorization List under 42 CFR 414.234, and names the exact return fields. This clearly separates it from siblings like pa_predict (prediction) and pa_status (status of a submitted request), since it is a deterministic list lookup.

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 clear operating context: a date of service defaulting to today, the condition under which state must be supplied (state-phased items), and a scope limitation (Original Medicare FFS). It does not explicitly name pa_predict or pa_status as alternatives, so routing between the three prior-auth tools still requires inference.

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