docs: add modifier ordering rule

Author: AlbertoCentonze

.gitignore

@@ -9,3 +9,5 @@ wheels/
 # Virtual environments
 .venv
 .idea
+
+site

docs/rules/index.md

@@ -15,6 +15,7 @@ This section documents the available rules in Natrix.
 | [NTX9](implicit-export.md) | Implicit Export | Important | Detects when a module exposes all its functions using `__interface__` |
 | [NTX10](unused-argument.md) | Unused Argument | Warning | Detects function arguments that are declared but never used |
 | [NTX11](argument-naming.md) | Argument Naming Convention | Warning | Ensures function arguments follow a specified naming convention |
+| [NTX12](modifiers-ordering.md) | Modifiers Ordering | Style | Enforces consistent ordering of function modifiers |
 
 ## Rule Categories
 

docs/rules/modifiers-ordering.md

@@ -0,0 +1,59 @@
+# Modifiers Ordering
+
+| Property | Value |
+|----------|-------|
+| Rule Code | `NTX12` |
+| Severity | Style |
+
+## Background
+
+Vyper allows multiple decorators on functions to specify visibility (@external, @internal, @deploy), mutability (@pure, @view, @nonpayable, @payable), and security properties (@nonreentrant). While the compiler accepts these decorators in any order, maintaining a consistent ordering improves code readability and makes the function's properties immediately clear to readers.
+
+## Purpose
+
+Enforces a consistent ordering of function modifiers in Vyper contracts. The recommended order is:
+
+1. **Visibility** decorators first (@external, @internal, @deploy)
+2. **Mutability** decorators second (@pure, @view, @nonpayable, @payable)
+3. **Security** decorators last (@nonreentrant)
+
+## Example
+
+```vyper
+# Non-compliant - incorrect ordering
+@view
+@external  # visibility should come before mutability
+def get_balance() -> uint256:
+    return self.balance
+
+@nonreentrant
+@external  # visibility should come before security
+@payable
+def deposit():
+    self.balance += msg.value
+
+# Compliant - correct ordering
+@external  # visibility first
+@view      # mutability second
+def get_balance_correct() -> uint256:
+    return self.balance
+
+@external     # visibility first
+@payable      # mutability second
+@nonreentrant # security last
+def deposit_correct():
+    self.balance += msg.value
+
+# Functions without explicit visibility (defaults to internal)
+# Non-compliant
+@nonreentrant
+@view  # mutability should come before security
+def internal_func() -> uint256:
+    return self.balance
+
+# Compliant
+@view         # mutability first
+@nonreentrant # security second
+def internal_func_correct() -> uint256:
+    return self.balance
+```

mkdocs.yml

@@ -57,5 +57,6 @@ nav:
     - Implicit Export (NTX9): rules/implicit-export.md
     - Unused Argument (NTX10): rules/unused-argument.md
     - Argument Naming Convention (NTX11): rules/argument-naming.md
+    - Modifiers Ordering (NTX12): rules/modifiers-ordering.md
   - API Reference: api/index.md
   - Development: development/index.md