Compare two or more products side by side. Use when the user asks to compare, says 'X vs Y', or wants to decide between options. Do not use for single product lookup — use get_product instead. Returns structured comparison with shared attributes, differences, tradeoffs, and a decision hint.
| Name | Required | Description | Default |
|---|---|---|---|
| products | Yes | Product titles or SKUs to compare (e.g. ['MIRA', 'CryoSculpt']) |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is clear. The description adds valuable behavioral details by stating it returns 'structured comparison with shared attributes, differences, tradeoffs, and a decision hint', which goes beyond the schema and annotations.
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?
Three tightly written sentences: purpose, usage guidance, and output summary. Every sentence adds value with no filler or redundancy.
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?
Given the simple input (one array parameter), strong annotations, and absence of an output schema, the description adequately covers what the tool does, when to use it, what it returns, and how it differs from siblings. No meaningful gaps.
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% — the 'products' parameter includes a clear description with format and example. The tool description doesn't add extra parameter-level semantics beyond what's in the schema, so 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?
The description clearly states the tool's function with a specific verb ('Compare') and resource ('two or more products side by side'). It also distinguishes from sibling tools by explicitly contrasting with get_product for single lookups, making its purpose unambiguous.
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?
Provides explicit usage conditions ('when the user asks to compare, says 'X vs Y', or wants to decide between options') and a clear exclusion with an alternative ('Do not use for single product lookup — use get_product instead'). This is textbook guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.