Unzip array of pairs into two arrays.
| Name | Required | Description | Default |
|---|---|---|---|
| pairs | Yes | JSON array of pairs, e.g., [[1,2],[3,4]] |
| Name | Required | Description | Default |
|---|---|---|---|
| code | No | ||
| error | No | ||
| pairs | No | ||
| array1 | No | ||
| array2 | No |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description carries full burden but fails to disclose edge cases (e.g., invalid input, empty arrays) or behavior beyond the basic operation.
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 description is a single sentence with no wasted words, efficiently conveying the tool's function.
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 presence of an output schema and the tool's simplicity, the description is adequate but could mention input validation or expected format more explicitly.
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 coverage is 100% (single parameter 'pairs' fully described in schema), but the description adds no additional meaning beyond restating the schema content.
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 'Unzip array of pairs into two arrays' uses a specific verb ('unzip') and resource ('array of pairs'), clearly distinguishing it from sibling tools like array_zip and array_slice.
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?
No guidance is provided on when to use this tool versus alternatives, nor any context for when not to use it, leaving the agent with no decision support.
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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