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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds that output is '% RDA per nutrient and deficiencies,' but an output schema exists, so that return detail is largely redundant and no auth, rate-limit, or data-source behavior is disclosed.

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 short sentences, front-loaded with purpose, then usage, inputs, and returns. Efficient with little waste, though the trailing 'See list_bundles' sentence adds marginal routing value.

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?

An output schema and safety annotations exist, but the core input described (foods with quantities) does not exist in the schema, leaving an agent unable to reconcile the description with the actual callable parameters. For a calculation tool whose main input is missing from the schema, the definition is materially incomplete.

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 description coverage is 0%, so the description must carry parameter meaning, yet it claims the input is a 'list of foods with quantities' while the schema exposes only 'age' and 'sex' with no food parameter at all. This actively misleads an agent about how to invoke the tool and never mentions the two real required parameters.

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: 'Check daily vitamin and mineral intake against RDA recommendations,' which is clear and concrete. It does not differentiate from close siblings such as calculate_daily_protein or calculate_recipe_nutrition; the 'See list_bundles for related cuisine calculators' pointer is a generic cross-reference, not a real disambiguation.

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?

'Use for nutrition tracking' gives a domain context but no when-to-use vs when-not, no prerequisites, and no named alternative among the many nutrition siblings. The list_bundles pointer implies a routing step but does not state the condition for choosing this tool over others.

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