diff --git a/etaf-context.el b/etaf-context.el
index 6919176..a521b72 100644
--- a/etaf-context.el
+++ b/etaf-context.el
@@ -177,7 +177,8 @@ also accepted and remains tracked by the current render effect."
         validated))))
 
 (defun etaf--theme-source (&optional default)
-  "Return the inherited Theme source without reading its reactive value."
+  "Return the inherited Theme source, using DEFAULT when none is provided.
+This does not read the source's reactive value."
   (etaf-inject 'theme default))
 
 (defun etaf--theme-source-value (source &optional default tracked-p)
diff --git a/etaf-renderer.el b/etaf-renderer.el
index 4033607..09a163e 100644
--- a/etaf-renderer.el
+++ b/etaf-renderer.el
@@ -78,7 +78,8 @@
        (string-prefix-p "on-" (substring (symbol-name property) 1))))
 
 (defun etaf--generated-host-ref (props path &optional site-token)
-  "Return the explicit or generated opaque Host reference."
+  "Return PROPS' explicit Host reference or one generated for PATH.
+SITE-TOKEN replaces PATH as the generated call-site identity when non-nil."
   (or (plist-get props :ref)
       (list 'etaf-host (or site-token (copy-sequence path)))))
 
@@ -326,7 +327,8 @@ the ordinary layout lowering path instead."
    (t nil)))
 
 (defun etaf--ebox-properties (props path &optional site-token)
-  "Project ETAF PROPS at PATH to canonical Ebox author facts."
+  "Project ETAF PROPS at PATH to canonical Ebox author facts.
+SITE-TOKEN supplies the stable generated Host identity when non-nil."
   (let* ((source-props (etaf--resolve-property-plist props))
          (props (copy-sequence source-props))
          ebox-props)
@@ -441,7 +443,7 @@ the ordinary layout lowering path instead."
                     props etaf--ebox-source-fields)))))
 
 (defun etaf--ebox-box-node (tag props children)
-  "Return one typed Ebox BoxNode TAG over canonical CHILDREN."
+  "Return one typed Ebox BoxNode TAG with PROPS over canonical CHILDREN."
   (let* ((declarations (etaf--ebox-declarations tag props))
          (layout (etaf--ebox-layout-config tag props declarations))
          (outer (if (plist-member props :outer)
diff --git a/etaf-runtime.el b/etaf-runtime.el
index 3843396..8ed035d 100644
--- a/etaf-runtime.el
+++ b/etaf-runtime.el
@@ -373,7 +373,8 @@ the sequential `etaf--pvec-put' contract."
 
 (defun etaf--runtime-theme-paint-value
     (runtime property token source resolved)
-  "Return RUNTIME's stable paint slot for PROPERTY TOKEN and RESOLVED value."
+  "Return RUNTIME's stable paint slot for PROPERTY TOKEN from SOURCE.
+RESOLVED is the current projected paint value."
   (if (not (and runtime
                 (etaf--runtime-theme-paint-property-p property)
                 (or (etaf-ref-p source) (etaf-computed-p source))))
@@ -1384,7 +1385,8 @@ reading Runtime storage fields."
 
 (defun etaf--runtime-register-host
     (runtime props path &optional site-token old-semantic)
-  "Register PROPS contributions for one semantic Host at PATH.
+  "Register PROPS contributions in RUNTIME for one semantic Host at PATH.
+SITE-TOKEN supplies its stable author call-site identity when non-nil.
 OLD-SEMANTIC supplies the already-read committed Host, when any."
   (let ((host-ref (etaf--generated-host-ref props path site-token))
         (tail props)
@@ -4017,7 +4019,7 @@ Generation, including its effects and Host contributions."
     found))
 
 (defun etaf--runtime-render-dirty-host-properties (runtime effect semantic)
-  "Resolve one reactive Host SEMANTIC into RUNTIME's candidate graph."
+  "Resolve EFFECT for Host SEMANTIC into RUNTIME's candidate graph."
   (let* ((base
           (or (gethash (etaf--semantic-host-semantic-id semantic)
                        (etaf-runtime-candidate-graph-nodes runtime))
@@ -4258,7 +4260,9 @@ Generation, including its effects and Host contributions."
 
 (defun etaf--runtime-render-keyed-range
     (runtime effect range component instance)
-  "Render only changed items in dirty keyed RANGE, or return nil."
+  "Render EFFECT's changed items in keyed RANGE for RUNTIME.
+COMPONENT and INSTANCE supply the retained owner environment.  Return nil when
+the range is not eligible for keyed incremental rendering."
   (let* ((expr (etaf--generation-effect-target effect))
          (snapshot-function (and (etaf--expr-p expr)
                                  (etaf--expr-range-snapshot expr)))