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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds the id-prerequisite workflow, but with no output schema it never says what a coverage result looks like (boolean per plan? per drug?) or how partial/no-coverage cases are reported.

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, zero filler, with the core purpose and the prerequisite ordering both front-loaded. Nothing restates the name or title.

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?

Safety and prerequisite context are covered, but for a batch lookup tool with no output schema the response shape and per-plan result semantics are unexplained. An agent knows how to call it but not how to interpret the return.

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 only 33% (only plan_ids is documented), but the description compensates by mapping medications→rxcuis (RxCUI identifiers) and doctors→npis (NPI identifiers) and stating where those ids come from. Array caps and defaults are already in the schema, so the remaining gap is minor.

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 (check) and two concrete resources (drug coverage by RxCUI, doctor network status by NPI) scoped to plans. This is clearly distinct from the sibling search_* and get_plan tools, which retrieve entities rather than evaluate coverage against a plan.

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?

Explicitly tells the agent to call search_drugs and search_doctors first to obtain the ids, which is the key prerequisite. It does not cover when to prefer get_plan or what to do when npis/rxcuis are omitted, so it stops short of full when/when-not guidance.

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