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Tools, multimodal inputs, and agent boundaries
Keep information from a webpage from becoming permission to act.
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Tools, multimodal inputs, and agent boundaries
Keep information from a webpage from becoming permission to act.
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Source-based teaching example · Fictional data · Reviewed 2026-10-03. Microsoft Mark · locally synthesized. On a small screen, use fullscreen for diagram details or read the transcript.
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0:00 · What you will learn
Keep information from a webpage from becoming permission to act.
What appears on screen
Keep information from a webpage from becoming permission to act.
0:06 · The idea
A page may contain text that tries to redirect the assistant. Treat that text as something to inspect, not a command from the user. Limit what the tools can actually do.
What appears on screen
A page may contain text that tries to redirect the assistant. Treat that text as something to inspect, not a command from the user. Limit what the tools can actually do.
0:20 · One useful term
Prompt injection. Instructions in untrusted content that try to change the assistant’s task. They may be visible or hidden.
What appears on screen
Instructions in untrusted content that try to change the assistant’s task. They may be visible or hidden.
0:31 · A worked example · 1
The task is to summarize three public pages. One page asks the assistant to upload local files. That request is outside the task.
What appears on screen
The task is to summarize three public pages. One page asks the assistant to upload local files. That request is outside the task.
0:44 · A worked example · 2
Read-only tools with no file-upload access help block that action.
What appears on screen
Read-only tools with no file-upload access help block that action.
0:51 · Your turn to think
Does a sentence on a webpage give permission to upload files? Pause and decide before continuing.
What appears on screen
Does a sentence on a webpage give permission to upload files? Pause the video if you need more time.
1:08 · Why this answer works
No. The same applies if the sentence appears in an image. Real permissions must be enforced outside the prompt.
What appears on screen
No. The same applies if the sentence appears in an image. Real permissions must be enforced outside the prompt.
1:19 · Check 1
Use only the needed sources and tools.
What appears on screen
Use only the needed sources and tools.
1:24 · Check 2
Do not add access when the task fails.
What appears on screen
Do not add access when the task fails.
1:30 · Check 3
Stop when the approved limits are reached.
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Stop when the approved limits are reached.
1:35 · Now try a different case
Open the lesson and try its different practice case. Use every check in the full task. Watching alone does not mark the lesson complete.
What appears on screen
Open the lesson Try the new case Check and revise The full task and its requirements are in the linked lesson.
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