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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is established. The description adds valuable context: it is not a product ranking, contains no affiliate links, and dictates the agent's behavior when sensitive data is mentioned. No contradiction with annotations.

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 front-loaded with the core purpose, followed by scope restrictions and safety instructions. It is somewhat lengthy but every sentence adds necessary context (purpose, exclusions, user-redirect behavior). No filler.

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?

Given the output schema exists and annotations cover mutability, the description is complete: it defines the tool's scope, exclusions, and handling of sensitive information. The agent has enough to select and invoke the tool appropriately without missing critical context.

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 0%, so the description must compensate. It clarifies that 'supplements' should be two to five items and that 'goal' refers to a shared goal for all supplements. However, it does not detail parameter formats, allowed values, or how supplement names should be provided, leaving room for ambiguity.

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?

Description clearly states 'Compare mapped human-evidence strength and limitations for two to five supplements for the same goal' – a specific verb, resource, and scope. It also explicitly distinguishes itself from 'product ranking or purchase recommendation', differentiating it from potential sibling tools like compare_supplements.

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?

Provides explicit when-to-use ('public, non-personal evidence questions') and when-not-to-use ('requests involving personal or sensitive health information') guidance. It also instructs the agent to redirect users to a qualified healthcare professional, making exclusions actionable.

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