The documentation for the --cli mode is a bit lacking, but I got there in the end:

  npx @modelcontextprotocol/inspector --cli \
    https://agentic-mermaid.dev/mcp \
    --method tools/call \
    --tool-name render_svg \
    --tool-args-json '{"source":"graph TD; A-->B","options":{"padding":24}}'

Equivalent with my mcp-explorer tool:

  uvx mcp-explorer call \
    https://agentic-mermaid.dev/mcp render_svg \
    -a source 'graph TD; A-->B' \
    -a options '{"padding":24}'

So yeah, they're pretty similar.

Then for my list command:

  uvx mcp-explorer list https://agentic-mermaid.dev/mcp

With the inspector one you would do:

  npx @modelcontextprotocol/inspector --cli \
    https://agentic-mermaid.dev/mcp \
    --method tools/list

Mine returns a human-readable list (unless you add --json), the inspector one returns a big dump of raw JSON.