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factreason_component_spec

Read-onlyIdempotent

Look up electronics component specs: pin assignments, voltage range, package, and alternatives. Pass exact part number or describe capability for matching suggestions.

Instructions

Look up electronics component pin assignments, voltage range, package, and alternatives. Pass exact partNumber for one component or query for a capability search; partNumber takes precedence if both are supplied. For exact lookups, set responseFormat="compact" for tokenizer-measured context savings; the backward-compatible default is "full". Uses metered access and returns matches or suggestions. Confirm critical values against the manufacturer datasheet.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`query`	No	Free-text capability search, e.g. "3.3V ARM MCU with SPI"
`partNumber`	No	Exact part number, e.g. "STM32F401RE"
`responseFormat`	No	Use compact for an exact part lookup; full preserves the legacy data response	full

Output Schema

TableJSON Schema

Name	Required	Description	Default
`data`	No
`hint`	No
`found`	No
`compact`	No
`message`	No
`results`	No
`partNumber`	No
`provenance`	No
`qualityScore`	No
`tokenMetrics`	No
`totalMatched`	No
`nearestMatches`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv2.0.4Aug 16, 2026

addedInput schema / properties / responseFormat

Added value: +{
+  "default": "full",
+  "description": "Use compact for an exact part lookup; full preserves the legacy data response",
+  "enum": [
+    "full",
+    "compact"
+  ],
+  "type": "string"
+}

removedOutput schema / properties / compact / additionalProperties
```
Removed value: -true
```
changedOutput schema / properties / compact / type
```
Previous value: -"object"New value: +"string"
```

addedOutput schema / properties / provenance

Added value: +{
+  "additionalProperties": true,
+  "type": "object"
+}

addedOutput schema / properties / qualityScore
```
Added value: +{
+  "type": "number"
+}
```

addedOutput schema / properties / tokenMetrics

Added value: +{
+  "additionalProperties": false,
+  "properties": {
+    "compactTokens": {
+      "type": "number"
+    },
+    "encoding": {
+      "const": "o200k_base",
+      "type": "string"
+    },
+    "fullTokens": {
+      "type": "number"
+    },
+    "reductionPct": {
+      "type": "number"
+    },
+    "savedTokens": {
+      "type": "number"
+    }
+  },
+  "type": "object"
+}

Changed7 schema fields changedv2.0.2Aug 14, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / anyOf

Added value: +[
+  {
+    "required": [
+      "partNumber"
+    ]
+  },
+  {
+    "required": [
+      "query"
+    ]
+  }
+]

changedInput schema / properties / partNumber / description

Previous value: -"Exact part number, e.g. \"STM32F401RE\", \"ESP32-WROOM-32E\""New value: +"Exact part number, e.g. \"STM32F401RE\""

addedInput schema / properties / partNumber / minLength
```
Added value: +1
```

changedInput schema / properties / query / description

Previous value: -"Alternative: free-text search, e.g. \"3.3V ARM MCU with SPI\""New value: +"Free-text capability search, e.g. \"3.3V ARM MCU with SPI\""

addedInput schema / properties / query / minLength
```
Added value: +1
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": true,
+  "properties": {
+    "compact": {
+      "additionalProperties": true,
+      "type": "object"
+    },
+    "data": {
+      "additionalProperties": true,
+      "type": "object"
+    },
+    "found": {
+      "type": "boolean"
+    },
+    "hint": {
+      "type": "string"
+    },
+    "message": {
+      "type": "string"
+    },
+    "nearestMatches": {
+      "items": {
+        "additionalProperties": true,
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "partNumber": {
+      "type": "string"
+    },
+    "results": {
+      "items": {
+        "additionalProperties": true,
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "totalMatched": {
+      "type": "number"
+    }
+  },
+  "type": "object"
+}

First observedv2.0.1Aug 14, 2026

TDQS

A4.7/5.0

Behavior5/5

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

Annotations already declare readOnlyHint and idempotentHint true, but the description adds valuable behavioral context: metered access, returns matches or suggestions, and a caveat to confirm values against the manufacturer datasheet. This goes beyond what annotations provide and gives the agent a clear picture of side effects and reliability.

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

Conciseness5/5

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

The description is three sentences, front-loaded with the core purpose, and every sentence contributes new information: lookup scope, usage modes, format guidance, metering, and a caution. No wasted words.

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?

Given the tool's moderate complexity (dual lookup modes, response format options, metered access), the description covers all essential guidance: input strategies, precedence, format preference, and data validity warning. The output schema exists, so return values need no explanation here.

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?

Schema coverage is 100% with parameter descriptions, but the description enriches semantics by explaining precedence behavior (partNumber takes precedence) and the practical distinction between responseFormat values. This adds value beyond the raw schema definitions, though it doesn't dive deep into each parameter.

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 opens with 'Look up electronics component pin assignments, voltage range, package, and alternatives,' which uses a specific verb and resource, making the tool's purpose immediately clear. It also differentiates from sibling tools like factreason_api_breaking_changes or factreason_integration_brief by focusing on component-level data.

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?

It explicitly explains when to use partNumber vs query, states the precedence rule, and advises setting responseFormat to compact for exact lookups. However, it does not explicitly compare to alternative sibling tools or state when not to use this tool, so it falls short of a 5.

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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