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

Annotations already declare a non-read-only, non-destructive create with openWorldHint, so safety is covered. The description adds genuinely useful behavior not in the annotations: values are per 100 g, and dish macros are computed by summing ingredients. It omits what happens when both macros and ingredients are supplied, permissions, and whether the created record is returned.

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 dense sentence with the creation mode front-loaded and no filler; the parenthetical about summed macros earns its place by explaining computed output.

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?

For a 9-parameter mutation with no output schema and zero schema coverage, the definition is thin: an agent still doesn't know the unit/format for category, whether macros and ingredients are mutually exclusive, or what identifier comes back. The two authoring modes it does describe are the most important omission it fixes, keeping it at minimum-viable rather than inadequate.

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 9 parameters at 0% schema description coverage, the description carries the full burden and only partially meets it. It explains the per-100 g unit convention and the ingredients summing behavior, but says nothing about category, sodium_mg, fiber_g, portion_label, quantity_grams, or the required/optional split.

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 and resource ('Adds a food') and distinguishes two creation modes: a food described by per-100 g macros, or a dish composed from ingredients. It does not name the sibling it contrasts with (update_food for edits, search_foods for finding food_ids), so sibling differentiation is only implicit.

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 two-mode phrasing ('with macros per 100 g, or a dish from ingredients') gives an agent an implicit branch for how to call it, but there is no explicit when-to-use versus update_food instead of create, and no stated prerequisites or exclusions.

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