Claude Code adds Tool(param:value) syntax for tool permissions

By Harsh Desai19 June 2026

TL;DR

Claude Code introduced Tool(param:value) syntax for permission rules. It enables blocking or allowing tool executions based on parameters and wildcards.

What changed

Claude-code now includes the Tool(param:value) syntax for permission rules. Developers apply this to block or allow specific tool executions through input parameters and wildcards. Vibe Builders and Basic Users gain more targeted options for managing tool behavior.

Why it matters

Developers working on secure workflows benefit when applying rules to concrete use cases such as restricting file operations to approved directories only. Basic Users run tasks with fewer broad blocks in place. Vibe Builders integrate the syntax into custom setups for precise parameter handling over earlier broad approaches.

What to watch for

Compare the new syntax against the standard permission syntax without parameters. Developers should verify by writing a sample rule with a wildcard value and testing it directly in a claude-code session.

Who this matters for

Vibe Builders: Use the Tool(param:value) syntax to restrict file operations to specific project directories.

Harsh’s take

Broad permission prompts are the primary friction point in agentic workflows. This update moves Claude Code toward a more autonomous state by allowing users to pre-approve specific, safe parameter patterns while hard-blocking risky ones. It is a practical security layer that reduces manual overhead.

Operators should immediately implement wildcard rules for their most frequent directory paths. This prevents the tool from asking for permission on every minor file read while ensuring it cannot stray into sensitive system folders. Granular control is the only way to scale agentic tools without constant human babysitting.

by Harsh Desai

Source:code.claude.com