Codex refuses ?codemode=false: tools/list has more than its 2,048-tool cap #262

Codex can't load the direct-tool surface (/mcp?codemode=false). It refuses any MCP server whose tools/list returns more than 2,048 tools, and drops the server at startup:

codex_mcp::rmcp_client: MCP server startup failed server_name="cf-stg-direct"
  error=tools/list exceeded the catalog limit of 2048 items

The model then reports that none of the server's tools are available.

Repro

Codex CLI 0.157.0, logged in to https://staging.mcp.cloudflare.com/mcp?codemode=false:

codex mcp add cf-stg-direct --url "https://staging.mcp.cloudflare.com/mcp?codemode=false"
codex mcp login cf-stg-direct
RUST_LOG=codex_mcp=debug codex exec "Call the cf-stg-direct MCP tool accounts_list once."

The result is the same with and without Codex's code_mode and mcp_2026_07_28 features.

Scope

• With the Forge catalogue (feat: build every API artifact from Forge in a daily container and serve mcp-tools.json directly #247), ?codemode=false lists 2,905 tools (docs, whoami and 2,903 endpoints).
• Production's current catalogue is larger: about 3,661 tools.
• The default Code Mode server (/mcp, four tools) is unaffected.
• OpenCode v2 loads the full catalogue and drives it through its own Code Mode, so the problem is the cap, not the catalogue's shape.