Chroma

There is no Context Tax to report, and that absence is the finding. tools/list never ran, so the chars/4 estimate we print on every other page has nothing to work with here: zero tools, zero bytes of schema, zero tokens, not because the server is lean but because it was never asked. That matters when you are budgeting a client's tool window, since an unmeasurable server is a hole in the plan rather than a cheap slot. A vector-store surface is normally small, since add, query, list and delete cover most of it, so the honest guess is that chroma-mcp lands under this batch's median once it boots. Guess is the operative word. We did not measure it.

It is a uvx launch of chroma-mcp over stdio, and the harness scraped no env-var names out of the failure, so there is no secret list to hand you. What there is instead is a working-directory contract nobody documents: chroma-mcp reads settings through pydantic-settings, which unconditionally tries to open a .env file in the process's current directory. Ours existed and was not readable by the probe user, and the traceback ends in a plain PermissionError on '.env' with an exit code of one. Fixes, in order of how much you will hate them: start the server from a directory with no .env, grant the running user read access to the one that is there, or set the client's cwd explicitly instead of inheriting whatever your editor happened to be in. The README also describes client, persistent, HTTP and Chroma Cloud modes selected by flags, which you will need to pick once the process survives long enough to read them.