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

With no annotations, the description carries the full burden and does so: it discloses pricing ($0.005/call), accepted chains/tokens, the pre-payment refusal of unknown names, licence attribution per source, and the 'information, not medical advice' disclaimer. These are all behaviours an agent must know before invoking.

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 dense but front-loaded with the resource and its sources, then payment mechanics, then the disclaimer. Every sentence earns its place, though the x402 chain/token enumeration is slightly heavy for a description field.

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?

No output schema exists, and the description compensates by listing exactly what the card returns (warnings, interactions, AE counts, recalls, dosing, dangerous combinations) plus licences and cost. An agent has everything needed to decide and correctly call it.

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 real meaning: it clarifies what values `name` accepts (brand/generic/substance) and explains the x402 `payment` round-trip that the schema only gestures at with 'base64 payload'. That is value beyond the structured field.

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 names a specific resource (a drug safety card) and enumerates its content sources: RxNorm normalisation, FDA label warnings/interactions, adverse-event counts, recalls, molecule facts, harm-reduction dosing. This is far more than restating the name and clearly separates it from the many market/token siblings.

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?

It states the accepted input forms (brand, generic, or substance like MDMA) and gives an explicit two-step payment protocol: call without `payment` for terms, sign, call again with `payment`. It does not name a sibling alternative for plain drug-name lookup, 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.