io.github.mrfentmen/spef-mcp

spef-mcp

Is the io.github.mrfentmen/spef-mcp MCP server down? No. It answered initialize and tools/list in the probe of 2026-11-13.

SPEF MCP: parse parasitics, validate units, nets, caps and resistances.

alive probed 2026-11-14 · unchanged since 2026-11-13

14tools

2.6ktokens in Claude Opus 5.5

1.3 %of Claude's 200k window

1.1×the median server

290 msto initialize

42 msto list tools

Run it: npx -y @mrfentmen/spef-mcp@1.0.0 (stdio, probed in a container with the network off)
Host: npmjs.com
Reports itself as: spef-mcp 1.0.0
Capabilities: tools
Instructions: none
Of a 1M window: 0.3 % of a 1M context window
Count: 2.6k tokens in Claude Opus 5.5, exact, measured 2026-11-13. With the Claude Code prefix mcp__…__ on each tool name: 2.8k. The o200k_base estimate is 1.4k. Counted again when the tool definitions change. Method.
Repository: https://github.com/mrfentmen/awesome-servers
Registry: active, updated 2026-11-13 · registry entry

Most expensive tools

The Claude column scales the o200k estimate of each tool by this server's ratio of exact to estimate, 1.85×.

Tool	≈ Claude tokens	o200k estimate	Share of this server
search	267	144	10 %
diff	243	131	9 %
get_record	221	119	8 %
write_file	217	117	8 %
list_records	215	116	8 %

These registry entries have the same tool names and the same schema sizes.

Other registry entries on npmjs.com, the ones next to this name; all of them.

The result of the latest probe, the tool count and the token cost. The feed has an entry for every probe that changed them.

Stops answering, comes back, tool set or cost changes. One confirmation mail first, a stop link in every mail.