explain_ingredientExplain one ingredient or E-number. For example 'E471', 'carmine', 'prawns', 'whey' or 'alcohol denat'. Returns the verdict for each school and the reasoning.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | The ingredient or E-number, for example E471, carmine, gelatin or alcohol denat. | |
| context | No | Whether the ingredient is in food or a cosmetic. Defaults to food. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnly, idempotent, non-destructive and openWorld behavior, so the bar is lower. The description adds genuinely useful context beyond them by disclosing the response shape: a verdict per school plus reasoning. It does not mention rate limits or how ambiguous names are resolved.
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?
Two sentences, zero filler, and the core purpose is front-loaded before the illustrative examples and the return-value note.
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, the description usefully summarizes what comes back (per-school verdicts and reasoning), which is the main gap a caller would have. The cosmetic/food context option is left to the schema, which is acceptable given its full coverage.
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 100%, so both parameters are fully documented in the schema, including the food/cosmetic enum and its default. The description's name examples duplicate the schema's, adding no meaning beyond it; baseline 3 is appropriate.
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 (Explain) and resource (one ingredient or E-number), and the scope word 'one' implicitly separates it from the bulk sibling check_ingredients. The concrete examples ('E471', 'carmine', 'prawns') remove any ambiguity about what counts as an ingredient.
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 only implied: the tool is clearly for a single lookup, which contrasts with check_ingredients, but the description never states when to pick this over that sibling or what prerequisites exist. No when-not guidance is given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.