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

With readOnlyHint, openWorldHint, idempotentHint, and destructiveHint already supplied by annotations, the description adds useful behavioral context: the data reflects real prescribing in the US population, is ranked by estimated people, and supports off-label/multi-use insights. No contradiction exists, though it does not describe edge cases like unknown drugs or sampling limits.

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?

The description is two sentences with no filler. The primary purpose and ranking behavior are front-loaded, and the second sentence justifies when the tool is valuable while issuing the key input instruction.

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?

Together with the schema and annotations, the description provides enough context for an agent to call the tool correctly: generic drug input is required, results are ranked by estimated people, and the use case is off-label/multi-use. It does not explicitly enumerate the output fields, though 'ranked by estimated people' strongly implies the main return structure.

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?

The input schema provides 100% parameter coverage, so the description need not repeat parameter details. The phrase 'Give a generic drug name' reinforces the required drug parameter but adds little beyond the schema's own description and examples.

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?

The description clearly states that the tool lists what a given drug is actually prescribed for in the US, ranked by estimated people, which is a specific verb-resource combination. It distinguishes itself from label/approval databases, though it does not explicitly name the reverse sibling meps_drugs_for_condition.

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 description explicitly frames the tool for off-label and multi-use questions that label or approval databases cannot answer, and instructs the user to provide a generic drug name. It does not explicitly state when not to use it or name sibling alternatives, 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.