You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.290,
ImprovementsSection of the release
Unclear It is not clear whether this check runs in every case or only under certain conditions.
What
MCP (Model Context Protocol) is the standard way programs offer Claude tools. When a call gives one of the app's own MCP tools a name containing a slash or backslash, Claude Code now checks the call before it runs and explains why in the permission prompt. The explanation reads: "This call gives one of [the app]'s own MCP tools a name with a slash in it, so it is checked before it runs."
Names that are clearly a full path, a home-folder path, a variable or a web address are not matched by this rule. They already had their own explanations.
Why
Relative paths, such as src/file.txt, passed to these tools now lead to a check and a clear reason, so they cannot slip through without notice.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtIt is not clear whether this check runs in every case or only under certain conditions.
