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

With no annotations, the description carries the full burden and does substantial work: it discloses the 200-item cap, the 50-text-item cap, that text items incur the same cost as resolve's phrase resolution, and the crucial missing-value semantics (never counted as zero, coverage reported, items lacking values listed). What it omits is failure behavior for unresolvable text and any rate-limit or auth expectations.

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 most important constraint (aggregate totals with per-item values) is front-loaded, and the missing-value paragraph is genuinely valuable. But the first sentence is an extremely long run-on packing limits, costs, and semantics together, and the nutrient-grouping detail duplicates the schema, making it harder to scan than necessary.

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?

There is no output schema, so the description must explain returns, and it does: per-item nutrients on the same fields in the total's unit, plus coverage and the list of items lacking a value. That covers most of what an agent needs to interpret results; only error/unresolved-text handling is left unaddressed.

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 67%, so the schema already documents id, text, unit, quantity, fields and locale in detail. The description contributes extra constraints not in the schema (the 50-text-item limit, the cost linkage to resolve) and clarifies that per-line values share the total's unit, but much of its nutrient-group explanation repeats what the fields schema description already says.

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 the resource (nutrient totals across foods, products, recipes and supplements) and the operation (aggregate totals plus per-item values), which is specific enough to distinguish it from siblings like compute_recipe or reference_values. It never explicitly contrasts itself with those siblings, so the differentiation is inferential rather than stated.

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 is implied by the meal/food-log scenario ('a meal or food log shows and edits each entry without subtracting'), giving a decent sense of the intended context. However, there is no explicit when-to-use or when-not-to-use guidance, and no naming of the alternatives (check_intake, compare, compute_recipe) that an agent would need to choose correctly.

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