diff --git a/.changeset/harness-neutral-subagent-language.md b/.changeset/harness-neutral-subagent-language.md
new file mode 100644
index 0000000..3e4db73
--- /dev/null
+++ b/.changeset/harness-neutral-subagent-language.md
@@ -0,0 +1,5 @@
+---
+"mattpocock-skills": patch
+---
+
+Drop Claude Code's tool and agent-type names from the subagent-dispatch instructions in `code-review`, `codebase-design`, and `improve-codebase-architecture`, so the step is followable on Codex and other harnesses.
diff --git a/skills/engineering/code-review/SKILL.md b/skills/engineering/code-review/SKILL.md
index 62a18e4..2d276fe 100644
--- a/skills/engineering/code-review/SKILL.md
+++ b/skills/engineering/code-review/SKILL.md
@@ -57,8 +57,6 @@ Each smell reads *what it is* → *how to fix*; match it against the diff:
 
 ### 4. Spawn both sub-agents in parallel
 
-Send a single message with two `Agent` tool calls. Use the `general-purpose` subagent for both.
-
 **Standards sub-agent prompt** — include:
 
 - The full diff command and commit list.
diff --git a/skills/engineering/codebase-design/DESIGN-IT-TWICE.md b/skills/engineering/codebase-design/DESIGN-IT-TWICE.md
index 49a7c42..8419ad6 100644
--- a/skills/engineering/codebase-design/DESIGN-IT-TWICE.md
+++ b/skills/engineering/codebase-design/DESIGN-IT-TWICE.md
@@ -18,7 +18,7 @@ Show this to the user, then immediately proceed to Step 2. The user reads and th
 
 ### 2. Spawn sub-agents
 
-Spawn 3+ sub-agents in parallel using the Agent tool. Each must produce a **radically different** interface for the deepened module.
+Spawn 3+ sub-agents in parallel. Each must produce a **radically different** interface for the deepened module.
 
 Prompt each sub-agent with a separate technical brief (file paths, coupling details, dependency category from [DEEPENING.md](DEEPENING.md), what sits behind the seam). The brief is independent of the user-facing problem-space explanation in Step 1. Give each agent a different design constraint:
 
diff --git a/skills/engineering/improve-codebase-architecture/SKILL.md b/skills/engineering/improve-codebase-architecture/SKILL.md
index b56969e..529761a 100644
--- a/skills/engineering/improve-codebase-architecture/SKILL.md
+++ b/skills/engineering/improve-codebase-architecture/SKILL.md
@@ -24,7 +24,7 @@ This command is _informed_ by the project's domain model and built on a shared d
 
 Read the project's domain glossary (`CONTEXT.md`) and any ADRs in the area you're touching first.
 
-Then use the Agent tool with `subagent_type=Explore` to walk the codebase. Don't follow rigid heuristics — explore organically and note where you experience friction:
+Then spawn a sub-agent to walk the codebase. Don't follow rigid heuristics — explore organically and note where you experience friction:
 
 - Where does understanding one concept require bouncing between many small modules?
 - Where are modules **shallow** — interface nearly as complex as the implementation?