beebjit-mcp

by acscpt

Overview Schema Source Related Servers Discussions Admin

Python

Local

read_registers

Retrieve the 6502 register state (A, X, Y, S, PC, cycles, flags) from an active BBC Micro emulator session.

Instructions

Return 6502 register state.

Returns a dict with keys A, X, Y, S, PC, cycles as integers, and F as an 8-character flag string from beebjit's debugger (each flag position shows an upper-case letter when set, a space otherwise).

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": {
      "session_id": "<session_id>"
    },
    "name": "read_registers"
  }
}

Input Schema

Name	Required	Description	Default
`session_id`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.1Jul 31, 2026

TDQS

B3.3/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It discloses the return format in detail (dict with A, X, Y, S, PC, cycles, and flag string), but does not explicitly state that it is read-only, requires an active session, or what happens on failure. This is partial transparency.

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 brief and front-loaded, with every sentence contributing useful information. It efficiently conveys the purpose and the exact return format without excess words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool is simple (one parameter) and has an output schema, so the description's detailed return format is a bonus. However, it lacks usage context and session_id semantics, making it slightly incomplete for an agent to invoke correctly in all scenarios.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has a single required parameter 'session_id' with no description, and the tool description does not mention it. With 0% schema coverage, the description fails to compensate, leaving the parameter's meaning and source completely unexplained.

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 'Return 6502 register state' with a specific verb and resource, distinguishing it from siblings like read_memory or disassemble. It also details the expected output keys, making the purpose unmistakable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

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. The description does not mention exclusions, prerequisites, or reference sibling tools, leaving the agent to infer usage from the name alone.

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