Skip to content

OpenCancer

by opencancer.ai · remote · no sign-in to list tools · v2.0.0 · published by ai.opencancer

Cancer patient expert: NCCN-grounded answers with sources, recruiting trials, and expert review.

Final · 1Changes · 2
CompareRegistry entry

5 tools: 1 do something that can't be undone, 2 change things and 2 only read.

Scanned Oct 21, 2026

1 check matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http opencancer https://opencancer.ai/api/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnopen_case

    The server marks "open_case" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "open_case" says "open": a word for a change.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

5 tools

Can't be undone 1Claude Code: ask
  • send_feedbackFlags an OpenCancer answer for human expert review, or sends feedback to the OpenCancer team.No findings

    Why it is in this group

    • The name "send_feedback" says "send": a word for sending, and what is sent cannot be taken back.
    Description, as the server wrote it
    Flags an OpenCancer answer for human expert review, or sends feedback to the OpenCancer team. Used when the user says an OpenCancer answer was wrong, unsafe, or incomplete, or wants to tell OpenCancer something (answer_id identifies the answer; message holds the user's words). Also used to report that an OpenCancer tool returned no usable answer (kind "missing_answer" with answer_id or tool, no message). Feedback is read by the OpenCancer team; it is not an urgent-care channel and no reply is sent through it.

    Annotations the server declares

    • title: Flag an answer or send feedback
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Changes things 2Claude Code: ask
  • ask_opencancerAnswers a cancer patient or caregiver question in plain language, grounded in NCCN Guidelines for Patients and medical literature.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Answers a cancer patient or caregiver question in plain language, grounded in NCCN Guidelines for Patients and medical literature. Covers what a diagnosis, stage, biomarker or test result means; treatment options; side effects and their management; questions for the oncologist; second opinions; living with cancer. Answers in the language of the question. Returns the answer, its sources, a disclaimer, a link to OpenCancer's care team, and an answer id. Emergencies, prognosis or life-expectancy questions, and questions about children return a safety message that routes to the care team instead of an answer. Educational information, not medical advice. Accepts no personal identifiers

    Annotations the server declares

    • title: Ask OpenCancer
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • open_caseReturns a link where a patient can start an expert review of their case by OpenCancer and Cancer Commons scientists (records, options, trial shortlist, next step).1 finding

    Why it is in this group

    • The name "open_case" says "open": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "open_case" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The name "open_case" says "open": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Returns a link where a patient can start an expert review of their case by OpenCancer and Cancer Commons scientists (records, options, trial shortlist, next step). The link only opens an intake page: no case is created and no records are sent. The patient enters their own details and personally confirms consent on that page. Accepts no names, contact details or records.

    Annotations the server declares

    • title: Get the expert review link
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 2Claude Code: allow
  • find_clinical_trialsLists clinical trials recruiting now for a cancer type, from ClinicalTrials.gov, optionally near a city, state or country and filtered by a biomarker, drug or treatment keyword and…No findings

    Why it is in this group

    • The name "find_clinical_trials" says "find": a word for reading.
    Description, as the server wrote it
    Lists clinical trials recruiting now for a cancer type, from ClinicalTrials.gov, optionally near a city, state or country and filtered by a biomarker, drug or treatment keyword and by phase. Returns up to 8 trials with NCT number, phase, sponsor, the sites closest to the requested place, a registry link, a link to the full search, and a link to an OpenCancer expert who can build a trial shortlist for a specific case. Listing a trial is not an eligibility decision; only the trial team can confirm eligibility

    Annotations the server declares

    • title: Find recruiting clinical trials
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • get_trial_detailsReturns one clinical trial from ClinicalTrials.gov by its NCT number: what it tests, phase, status, last registry update, ages, the inclusion and exclusion criteria in their origin…No findings

    Why it is in this group

    • The name "get_trial_details" says "get": a word for reading.
    Description, as the server wrote it
    Returns one clinical trial from ClinicalTrials.gov by its NCT number: what it tests, phase, status, last registry update, ages, the inclusion and exclusion criteria in their original wording, recruiting sites with their status, study contacts, and the registry link. Eligibility is confirmed only by the study team

    Annotations the server declares

    • title: Get clinical trial details
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 2.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http opencancer https://opencancer.ai/api/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__opencancer__find_clinical_trials",
      "mcp__opencancer__get_trial_details"
    ],
    "ask": [
      "mcp__opencancer__ask_opencancer",
      "mcp__opencancer__open_case",
      "mcp__opencancer__send_feedback"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as opencancer. Review it before you use it.