mcp-bbc-goodfood

Scale a list of ingredients

scale_ingredients

Read-onlyIdempotent

Scale recipe ingredient quantities for a different serving count using a factor or from/to servings, with results labeled exact, adjusted, or unchanged.

Instructions

Put a list of ingredient lines to a different number of people. Pass 'factor', or else the pair 'from_servings' and 'to_servings'. Quantities are recomputed by this server and not by the site, and every line says under 'scaling' whether the arithmetic landed exactly, whether the figure was moved to stay usable in a kitchen, or whether the line carried nothing to multiply.

Input Schema

TableJSON Schema

Name	Required	Description
`factor`	No	What to multiply every quantity by. Pass this or the servings pair, never both.
`ingredients`	Yes	The lines to scale, as a recipe writes them, such as '200g plain flour'.
`to_servings`	No	How many people it should feed.
`from_servings`	No	How many people the list feeds as written.

Output Schema

TableJSON Schema

Name	Required	Description
`notes`	Yes
`factor`	Yes	What every quantity was multiplied by.
`source`	Yes
`ingredients`	Yes
`scaled_count`	Yes	Lines whose arithmetic landed exactly.
`rounded_count`	Yes	Lines whose figure was moved.
`unscaled_count`	Yes	Lines that carried no quantity to multiply.

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv1.1.0Sep 10, 2026
- removedOutput schema / properties / ingredients / items / properties / amount / anyOf
```
Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / ingredients / items / properties / amount / type
```
Added value: +[
+  "number",
+  "null"
+]
```
- removedOutput schema / properties / ingredients / items / properties / amount_max / anyOf
```
Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / ingredients / items / properties / amount_max / type
```
Added value: +[
+  "number",
+  "null"
+]
```
- removedOutput schema / properties / ingredients / items / properties / unit / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / ingredients / items / properties / unit / type
```
Added value: +[
+  "string",
+  "null"
+]
```
AddedAug 29, 2026

TDQS

A4.6/5.0

Behavior5/5

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

The description goes beyond the annotations by revealing that quantities are recomputed server-side, not by the website, and explains what each ingredient line will state under 'scaling'. This tells the caller what to expect and that the operation is non-destructive and idempotent. This aligns with the readOnly/idempotent annotations without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is relatively brief and field-oriented. It leads with the primary purpose, covers the parameter modes, and includes the useful scaling behavior. The sentence about scaling statuses is a bit long, but it earns its place because it describes what to expect in the output.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description is sufficient for an agent to know when to use the tool, which keys to pass, and what the output will say about each line. Combined with an output schema, full parameter schema coverage, and annotations, no critical behavioral details are missing for safe and correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already provides descriptions for all 4 parameters, so the baseline is adequate. The description adds value by explaining the mutually exclusive relationship between 'factor' and the servings pair, something the schema alone does not emphasize. It also gives semantic meaning to the scaling status output without repeating schema details.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a strong verb and resource: it scales a list of ingredient lines to a different number of people. It also distinguishes the tool's operation from the siblings (search, listing, fetching) by naming the computation mode. The added detail about 'factor' or 'servings pair' makes the purpose precise.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains exactly how the tool should be invoked: pass 'factor' or the 'from_servings'/'to_servings' pair. It clearly communicates the mutually exclusive parameter use. It does not explicitly discuss when to use this tool versus the siblings, but the tool's purpose is sufficiently distinct for an agent to select it without deep inference.

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

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