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

Annotations already declare readOnlyHint and openWorldHint, but the description adds real value beyond them: the authoritative source (NIH ODS fact sheets), the coverage limit ("Not exhaustive"), the privacy guarantee ("Never logged"), and that timing advice is part of the result. It does not describe result shape or how conditions alter recommendations in any depth, keeping it short of a 5.

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?

Three tight sentences, front-loaded with what the tool does, followed by the alternative-tool routing and the scope caveat. Every clause carries information; nothing is padding.

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 helpfully signals that timing advice is returned and that coverage is not exhaustive. It is nearly complete, though it never clarifies behavior when all three optional parameters are omitted, a real gap given zero required parameters.

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 schema already documents all three parameters in detail, including enum meanings for conditions. The description's examples ("warfarin", "Synthroid", levothyroxine/calcium timing) largely duplicate what the schema shows, so the baseline 3 is appropriate.

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: which nutrients interact with given medications or conditions, sourced from NIH ODS fact sheets, including timing advice. It explicitly distinguishes itself from the sibling stack_analyze ("to check an actual stack, pass medications to stack_analyze instead"), so an agent can route without opening either schema.

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 an explicit when-to-use condition (checking interactions for medications/conditions, no product list needed) and names the alternative tool plus the condition that selects it (an actual product stack goes to stack_analyze). It also sets expectations with "Not exhaustive."

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