embedcalc-mcp

Endianness / Byte Swap Converter

embedcalc_endian_swap

Read-onlyIdempotent

Convert hex byte sequences into big, little, mid-little (BADC), and mid-big (CDAB) endian formats. Useful for debugging Modbus register order and mixed-endian protocols.

Instructions

Show a hex byte sequence in all endianness orderings: big (ABCD), little (DCBA), mid-little/byte-swapped halfwords (BADC), mid-big/halfword-swapped (CDAB).

Args: hex (string) — e.g. '0x12345678' or 'DEADBEEF'; odd nibble counts get a leading zero. Returns (structured): { big, little, mid_little_badc, mid_big_cdab (null when < 4 bytes), bytes }. Example: 12345678 -> little 78563412, BADC 34127856, CDAB 56781234. Useful for Modbus register order and mixed-endian protocol debugging.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "hex": "<hex>"
    },
    "name": "embedcalc_endian_swap"
  }
}

Input Schema

Name	Required	Description	Default
`hex`	Yes	Hex byte sequence (with or without 0x)

Output Schema

Name	Required	Description
`big`	Yes
`bytes`	Yes	Original bytes, big-endian order
`little`	Yes
`mid_big_cdab`	Yes
`mid_little_badc`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Jul 11, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations already indicate read-only and idempotent. The description adds that odd nibble counts get a leading zero, and the return includes null for mid-big when <4 bytes, which is useful behavioral detail beyond annotations.

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: purpose, argument details, example and use case. Every sentence adds value, no fluff.

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 tool is simple with one parameter and structured output. The description covers input format, output fields (including null case), and a real-world usage scenario. Output schema exists but description complements it well.

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 describes the 'hex' parameter. The description adds examples ('0x12345678' or 'DEADBEEF') and clarifies handling of odd nibble counts, providing meaningful extra context.

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 clearly states the tool converts a hex byte sequence into all endianness orderings, listing specific outputs (big, little, mid-little, mid-big) and giving an example. This distinguishes it from sibling calculators.

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 ends with 'Useful for Modbus register order and mixed-endian protocol debugging', providing clear usage context. No explicit when-not-to-use, but the tool's purpose is specific enough among siblings.

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