Symptom page
Property keys like uids[] → missing tools
Claude Code 2.1.282 dropped subscriptions_list from public pushpad-mcp@0.1.1 because two property names contained brackets. Renaming those keys got the tool listed again.
Symptom
- One (or more) tools missing in Claude Code while other tools from the same server list.
- Debug log resembling: property key
uids[]does not match/^[a-zA-Z0-9_.-]{1,64}$/. - Inspector / another host may still list the tool.
How to judge
Differential: wire tools/list includes the tool; Claude Code does not. Inspect every inputSchema property name against the host’s accepted pattern. The checker often stops at the first bad key — a log that names uids[] does not prove tags[] is fine.
Full sample write-up (listing stage only, not commissioned): Work — pushpad-mcp brackets.
Host / version notes
Observed on Claude Code 2.1.282, MCP negotiation 2025-11-25. The Tools section of that revision does not itself define that regex; the log attributes the restriction to the Anthropic API path Claude Code uses. Later Claude Code builds may differ — a live recheck on the version you care about is the point of the paid check.
Next step
Run free Exactlane Preflight for the static contract. If Claude Code still drops or rejects tools after a PASS — or you already know you need a live host run — the public paid offer is the Claude Code Compatibility Check (US$150) or Check + Bounded Fix (US$300).