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

Annotations only declare readOnlyHint and openWorldHint; the description goes beyond them by disclosing the per-call price ($0.01 USDC via x402), which is real operational context an agent needs before invoking. It also enumerates the returned fields (macro split, USDA match per ingredient), though it says nothing about failure modes for unmatched or ambiguous ingredients.

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?

A single front-loaded sentence that names the resource, the input format, the output fields, and the price in that order. It is dense and slightly run-on, but each clause carries information an agent would otherwise have to guess.

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 and only two loosely documented parameters, the description carries most of the burden and does so: it explains what goes in, what comes back, and what it costs. The remaining gap is the absence of routing guidance relative to the `nutrition` sibling.

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?

With schema coverage at 50%, the description does useful work by spelling out that amounts can be household units (cups, tbsp, grams, pieces) and that servings drives the per-serving vs. total split. However, it never clarifies what `servings` semantically represents (yield count vs. divisor) or the exact ingredient line grammar, so the compensation is partial.

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 states a specific resource (nutrition facts for a whole recipe) and defines the operation precisely, including that it takes raw ingredient lines plus servings and returns per-serving and total nutrient values. It implicitly separates itself from the sibling `nutrition` by emphasizing 'whole recipe', but never names that sibling, so differentiation is left to inference.

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?

Usage context is implied rather than stated: an agent can infer this is the tool for multi-ingredient recipe analysis because the description requires 'ingredients with household amounts ... and servings'. There is no explicit when-to-use/when-not guidance and no pointer to the single-ingredient `nutrition` sibling for the alternative case.

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