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

Annotations already establish the full safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds provenance (figures come from the plan's own Benefit Schedule) and the granularity of the result, but says nothing about failure modes for a bad/unknown cert or rate limits; with an output schema present, return-shape detail is not needed here.

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?

Front-loads the core purpose, then the enumeration of covered items, then example queries — a sensible order. The middle sentence is long and runs several categories together, but almost every clause carries distinct information.

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 an output schema handling return values, annotations handling safety, and a single well-documented required parameter, the description covers purpose, scope, and usage context adequately. A minor gap is no guidance on what happens when the cert is unknown or how this differs from sibling term/option lookups.

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% and the single `cert` parameter is fully documented in-schema with a format example (F00070, F00070-06-000-02). The description adds no parameter-level meaning, which is the expected baseline when the schema does all the work.

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+resource: it returns what a single plan pays, item by item, sourced from that plan's own Benefit Schedule, and enumerates the exact benefit categories (room and board, hospital charges, surgeon's fee, imaging, cancer, psychiatric) plus limits and room class. This is far more specific than a name restatement, though it never explicitly contrasts itself with near-neighbors like plan_terms, plan_options, or compare_plans.

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 concrete triggering questions — "what does this cover", "is surgery covered in full", "does it include outpatient" — which tells the agent the right situations to reach for this tool. There is no explicit when-not guidance or named alternative (e.g. use compare_plans for multiple plans), so it stops short of a 5.

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