Claude Code shipped v2.1.178 on June 15 with several changes that matter a lot for anyone building or operating multi-agent systems. The headline feature — Tool(param:value) permission syntax — closes a significant governance gap that’s been a pain point for teams using Claude Code in complex agentic pipelines.

Tool(param:value): Granular Permission Control

Previously, Claude Code’s permission system worked at the tool level: you could allow or block a tool entirely, but you couldn’t restrict how a tool was called. This meant that if you wanted to prevent Claude from spawning Opus-class subagents (expensive, slow, overkill for many tasks), you either had to block agent spawning entirely or rely on prompting.

v2.1.178 changes this with Tool(param:value) syntax. You can now write permission rules that match on a tool’s input parameters. The canonical example from the release notes:

Agent(model:opus)

This rule blocks the spawning of subagents that use Opus as their model, while leaving other model variants (Sonnet, Haiku, etc.) unrestricted.

The system also supports * wildcards. For example, a pattern like Agent(model:claude-opus*) would match any Opus variant by prefix. This is valuable for:

  • Cost control: Block expensive models from spawning automatically in automated pipelines
  • Compliance: Restrict certain models in environments with data governance requirements
  • Behavioral control: Prevent high-autonomy models from being invoked in contexts that need guardrails

This feature is directly useful for OpenClaw skill authors building multi-agent orchestration — the same principle applies when controlling which models downstream agents can invoke.

Nested Skills Directories with Proximity-Based Precedence

Claude Code’s skills system has gotten a meaningful upgrade. Previously, skills loaded from the root .claude/skills directory. In v2.1.178, nested .claude/skills directories now load when you’re working on files in that directory tree.

The disambiguation rule is clean: when you’re in a subdirectory that has its own .claude/skills/ folder, its skills take precedence. If a skill name clashes with a parent or project-level skill, the nested version appears as <dir>:<name> so both remain available without collision.

This matters for monorepos and large codebases where different subdirectories have different working conventions, tools, or project-specific helpers. You can now have a backend/ directory with backend-specific skills and a frontend/ directory with frontend-specific ones, and Claude Code automatically picks up the right context based on where you’re working.

The same proximity logic extends to agent configs, workflow definitions, and output-style settings — the closest configuration to your working directory wins when names collide.

Auto Mode: Subagents Pre-Evaluated Before Launch

This is a quieter change but it closes a real security gap. In auto mode, Claude Code can spawn subagents to handle subtasks. The problem: previously, a subagent could be launched and then request a blocked action — meaning the reviewer saw the request after the subagent was already running, creating awkward mid-task intervention scenarios.

v2.1.178 adds pre-evaluation of subagent spawns by the classifier before launch. If a subagent’s planned first action would be blocked, the spawn is blocked before it starts. This makes the approval/review flow much cleaner in automated pipelines and prevents the “started work I shouldn’t have” failure mode.

Quality-of-Life Improvements

The release also includes several workflow improvements:

  • /doctor overhaul: Consistent flat tree layout across all sections, clearer section status icons, and highlighted command names. If you’ve used /doctor to debug Claude Code issues, it’s much more readable now.
  • Workflow keyword change: The workflow trigger now uses a purple shimmer highlight and only fires on explicit phrases like “run a workflow” or “workflow:” — not on casual mention of the word. Fewer false triggers in conversational use.
  • Remote Control error messages: Connection failures now show a persistent red /rc failed indicator in the footer, with clearer explanations of whether a failure is a gate, check failure, stale entitlement, or org policy.
  • /bug improvements: Now requires a description before submitting, and no longer uses model-refusal text as the GitHub issue title (a surprisingly common source of confusing bug reports).

For OpenClaw Skill Authors

The Tool(param:value) permission syntax and nested skills discovery are both directly applicable to OpenClaw users building multi-agent skills. If you’re defining skills that spawn subagents, you can now be more precise about what downstream agents are allowed to do — without blocking agent spawning entirely. Worth reviewing your existing skill permission configurations in light of this release.

Sources

  1. Claude Code Changelog — code.claude.com
  2. CHANGELOG.md on GitHub — anthropics/claude-code

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260615-2000

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