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The cancel-reservation MCP tool has a broken schema

  • April 21, 2026
  • 2 replies
  • 12 views

LeviRenza
New Participant

"The cancel-reservation MCP tool has a broken schema — it returns 'Invalid schema for function hospitable__cancel-reservation: In context=(), object schema missing properties' on every agent interaction. This is blocking all other tools from working properly. Using OpenClaw 2026.4.14 with the Hospitable MCP at https://mcp.hospitable.com/mcp. Please fix the tool schema urgently.

2 replies

LeviRenza
New Participant
  • Author
  • New Participant
  • April 21, 2026

We isolated the issue to the Hospitable MCP server. When the hospitable MCP connection was removed from OpenClaw, the random schema errors stopped immediately, while Discord and WhatsApp continued working. The failing tools included hospitable__cancel-reservation and hospitable__get-community-user. This strongly suggests the remote MCP server is exposing one or more tool input schemas in a format OpenAI/GPT-5.4 rejects — most likely type: object schemas missing a properties field, and possibly other strict-schema requirements. Please review the MCP tool definitions for OpenAI compatibility.


Nik Logachev
Hospitable Team Member
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  • Hospitable Team Member
  • April 21, 2026

Thanks for reporting, ​@LeviRenza . We’re on it. The challenge at the moment is solving tool + context bloat. We’re going to be at 40+ tools soon, and many more after that, some of them already having heavy schemas. This has lead to some agents starting to fail early. We’re experimenting with different ways of exposing lightweight schemas that agents can autonomously expand.

In our internal testing, agents typically *can* interpret the latest schema that we proposed, but it seems to depend on the client harness.