Compare requested product attributes with an offered variant and list missing or mismatched fields. FREE during validation. No key, credits, wallet or preparation needed. Supply your task in input. Existing source and input limits apply.
| Name | Required | Description | Default |
|---|---|---|---|
| input | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| extra | Yes | ||
| scope | Yes | ||
| matches | Yes | ||
| missing | Yes | ||
| mismatched | Yes |
Changes observed during successful MCP inspections.
Input schema / properties / maxPriceMicroUsdRemoved value: -{
- "description": "Optional legacy field; ignored in free mode.",
- "minimum": 0,
- "type": "integer"
-}Input schema / properties / requestIdRemoved value: -{
- "description": "Optional legacy field; ignored in free mode.",
- "type": "string"
-}Input schema / properties / maxPriceMicroUsd / descriptionPrevious value: -"Explicit maximum new debit; 0 means recovery only."New value: +"Optional legacy field; ignored in free mode."Input schema / properties / maxPriceMicroUsd / maximumRemoved value: -999999999999Input schema / properties / requestId / descriptionPrevious value: -"Persist the ID returned by agent_utilities_prepare. Reuse after uncertainty."New value: +"Optional legacy field; ignored in free mode."Input schema / properties / requestId / patternRemoved value: -"^\\d{13}_[A-Za-z0-9_-]{16,80}$"Input schema / requiredPrevious value: -[
- "input",
- "requestId",
- "maxPriceMicroUsd"
-]New value: +[
+ "input"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the safe-read profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description does add useful context beyond them: the operation is free, requires no key/credits, and is subject to existing source and input limits. It does not explain what the limits actually are or note the non-idempotent hint.
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 purpose sentence is front-loaded and effective, but the following four sentences are largely commercial boilerplate, and "Supply your task in input" is filler that conveys no actionable information. Roughly half the text does not earn its place.
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 exists so return values need no explanation, but with a nested 0%-documented parameter the description should carry the format burden and does not. Limits are referenced without being specified, leaving the agent unable to construct a correct 'requested'/'offered' payload from the description alone.
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% and the single parameter is a nested object with required 'requested'/'offered' sub-objects capped at 100 properties each. The description only says "Supply your task in input" and vaguely alludes to "input limits", giving no attribute key/value format, no statement of the 100-property cap, and no meaning for the nested structure.
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 (compare) plus both resources (requested product attributes vs. an offered variant) and names the output (missing/mismatched fields), so the operation is unambiguous. It does not, however, distinguish itself from adjacent siblings such as commerce_feed_page_compare or agent_utilities_page_delta_preview.
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 only usage signal is commercial/availability ("FREE during validation", "No key, credits, wallet or preparation needed"), which is not when-to-use guidance. There is no statement of when this comparison applies versus the sibling compare/diff tools, nor any exclusion conditions.
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.