2026-09-22 • 5 min read • Fix
How to Reduce Hallucinations With Better MCP Context
How to give an agent the page that holds the fact, require a citation, and ask one question that page does not answer.
An assistant that has not seen your docs will still describe your API. The
description will be fluent. The field name will be whatever was common in
general knowledge, which is how customers get told to send file on an
upload that the docs renamed to document.
The fix is putting that page where the assistant can retrieve it, and treating a missing citation as an answer you do not send.
What better context is
The page that holds the fact, on a server the client actually calls, with a link in the reply. When nothing in your content matches, the server says so before it says anything else, and the client is told to pass that on. That behavior is the part we care about in Choosing the right context.
Invented function names are the coding version of the same failure, in Vibe coding and the function that does not exist.
Why the page has to be connected
A warning in the prompt does not contain the field name. The docs do.
A paste helps one chat. The server is the same page on the next chat, and it updates when you refresh the source. That arrangement is Turn your documentation into AI context.
A guessed answer on a question the docs do not cover means the client filled the gap itself. You want the server to say the content does not cover it.
Make the server in MCP Studio
Write the fact down from the page, not from memory. "The upload field is
document."
MCP Studio is the no-code builder on
Appa Tools. Open the
wizard. You do not write any code.
- Add the site, repo, or PDF that states the field name. Leave the rest of the company site off this server. A nearby marketing sentence is how the wrong paragraph gets in.
- Select search and question answering. Add code example lookup when the mistake is a method that should come from the repository. See Give an AI agent access to your GitHub repository.
- Deploy and connect the client. Confirm a tool call. No tool call means you are not looking at MCP context yet. The order of checks is Debug an MCP server.
Check that it works
Ask which field the upload endpoint accepts. Accept the reply when it says
document and the citation is the page you wrote the fact down from.
Then ask for the office wifi password, or anything else the sources do not contain.
You: What is the office wifi password?
Assistant: Nothing in this server's content covers an office wifi password. The closest material is the upload field reference, which is a different subject. You would need to add that document as a source.
A guessed network name means the client filled the gap itself.
If the field name is still wrong
If the citation is the right page and document is missing from the passage,
the sentence is under the wrong heading. Move it. See
Make your documentation AI-ready.
The server returns the words on the page. It does not repair them.
Two documents that disagree should not both be unlabeled sources. Prefer the one you will stand behind, or disconnect the other. That case is returning the wrong information.
Connect the page that holds the fact today
Connect the page that holds the fact today.
Open MCP Studio, add the upload docs, and deploy. Ask which field to send.
Keep the server when the reply says document and cites that page.