diff --git a/index.bs b/index.bs
index 48c44a1..4274a31 100644
--- a/index.bs
+++ b/index.bs
@@ -361,8 +361,8 @@ The <dfn method for=ModelContext>registerTool(<var>tool</var>, <var>options</var
 1. If |tool owner| is not [=Document/fully active=], then return [=a promise rejected with=] an
    "{{InvalidStateError}}" {{DOMException}}.
 
-1. If this's [=surrounding agent=]'s [=agent cluster=]'s [=is origin-keyed=] is false
-   and this's [=relevant settings object=]'s [=environment settings object/origin=]'s
+1. If [=this=]'s [=surrounding agent=]'s [=agent cluster=]'s [=is origin-keyed=] is false
+   and [=this=]'s [=relevant settings object=]'s [=environment settings object/origin=]'s
    [=origin/scheme=] is not <code>"file"</code>, then return [=a promise rejected with=] a
    "{{SecurityError}}" {{DOMException}}.
 
@@ -409,9 +409,9 @@ The <dfn method for=ModelContext>registerTool(<var>tool</var>, <var>options</var
 
 1. Let |promise| be [=a new promise=] created in [=this=]'s [=relevant realm=].
 
-1. Let |signal| be |options|'s {{ModelContextRegisterToolOptions/signal}}.
+1. If |options|'s {{ModelContextRegisterToolOptions/signal}} [=map/exists=], then:
 
-1. If |signal| [=map/exists=], then:
+   1. Let |signal| be |options|'s {{ModelContextRegisterToolOptions/signal}}.
 
    1. If |signal| is [=AbortSignal/aborted=], then return [=a promise rejected with=]
       |signal|'s [=AbortSignal/abort reason=].
@@ -489,7 +489,7 @@ The <dfn method for=ModelContext>getTools(<var>options</var>)</dfn> method steps
 1. If |toolRequestor| is not [=Document/fully active=], then return [=a promise rejected with=] an
    "{{InvalidStateError}}" {{DOMException}}.
 
-1. If this's [=surrounding agent=]'s [=agent cluster=]'s [=is origin-keyed=] is false and this's
+1. If [=this=]'s [=surrounding agent=]'s [=agent cluster=]'s [=is origin-keyed=] is false and [=this=]'s
    [=relevant settings object=]'s [=environment settings object/origin=]'s [=origin/scheme=] is not
    <code>"file"</code>, then return [=a promise rejected with=] a "{{SecurityError}}"
    {{DOMException}}.