Permissions worth refusing
Grant the narrowest thing that makes the job possible, and prefer a listing that asked for less.
Look at a permission list and know which entries to push back on before you install anything.
How Permissions worth refusing works, in one picture
The same argument as the text, as a chain. Each step is what makes the next one possible.
- 1
Write access when the job is reading
A tool that summarises, searches, analyses or reports does not need to write. If it asks, the usual reason is that the maker built one broad integration rather than two narrow ones.
That is a convenience decision by somebody who is not carrying your risk. Prefer the listing that split them.
- 2
Open ended command execution
There is a real difference between a server that runs a fixed set of named commands and one that will run whatever string it is given. The first has a list you can read. The second has a list that depends entirely on what the model decides to say.
Our scan distinguishes them, and the listing says which it is. Treat open ended execution as something you grant deliberately, in an environment you would not mind losing.
This is the single highest consequence permission on the site. Nothing else is close.
- 3
Unbounded outbound network access
A listing that declares which hosts it may contact can be checked. One that may contact anything cannot, and that is also the shape of the SSRF weakness that a large 2026 scan found in more than a third of URL-accepting MCP servers.
Prefer a declared egress list. Where there is not one, assume anything the software reads could leave.
- 4
Credentials that are not scoped to the task
Where a listing needs a key, give it one issued for this purpose with the narrowest scope that works, and rotate it if you stop using the listing.
Never hand over a personal token that has your own full access attached. If the maker's setup instructions ask for one, that is worth an email before it is worth an install.
You have looked at a listing you were considering and identified at least one permission you would ask about.
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Grant the narrowest thing that makes the job possible, and prefer a listing that asked for less.
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