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

Annotations already establish readOnly/idempotent/non-destructive, and the description adds meaningful behavioral context: it is educational, never diagnoses, does not store a health record, does not create a cart, excludes PHI/free-text symptoms, and revalidates selections against the catalog. There is no contradiction with the 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?

Four sentences, each earning its place: what is returned, the custom_only exception, the revalidation guarantee, and the safety boundary. The most important behavioral information is front-loaded.

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 a complete input schema (100% parameter coverage), an output schema present, and annotations covering readOnly/idempotent behavior, the description adds the one missing layer: safety constraints, catalog revalidation, and the educational non-clinical stance. Nothing needed to invoke the tool correctly is absent.

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. The description earns one extra point by clarifying the cross-parameter relationship between custom_only and maxBudgetUsd ('A custom_only request with maxBudgetUsd excludes standard panels') and by bounding the semantic scope of concern/inputs with the PHI and free-text exclusion.

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 uses a specific action ('Returns') and a concrete resource ('a controlled educational Essential, Advanced, Max, or exact-budget Build Your Own Panel starting point'), which is far more informative than the title and clearly separates this from catalog-listing siblings. Phrases like 'educational' and 'never diagnoses' reinforce that this is a recommendation function, not a clinical or ordering tool.

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 implies when to call it by positioning it as a recommender and by explaining the custom_only/maxBudgetUsd behavior. However, it never names an alternative such as start_guided_panel_builder or search_lab_catalog, so an agent gets no explicit when-to-use versus when-not-to-use guidance.

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