Rewrite 548 skill descriptions to the activation rubric

Each rewritten description now states both what the skill does (concrete
capability, named tools/artifacts) and an explicit when-to-use trigger,
improving agent discovery/activation. Grounded in each skill's own body;
changes confined to the `description` field only (bodies and all other
frontmatter untouched). Produced by a gated audit->rewrite->recheck loop
(548 -> 0 flagged) with a sampled anti-invention check (0 ungrounded).

Schema: 817/817 pass. Framework-ID gate: 0 defects.

skills/exploiting-constrained-delegation-abuse/SKILL.md

@@ -1,8 +1,12 @@
 ---
 name: exploiting-constrained-delegation-abuse
-description: Exploit Kerberos Constrained Delegation misconfigurations in Active Directory
-  to impersonate privileged users via S4U2self and S4U2proxy extensions for lateral
-  movement and privilege escalation.
+description: >-
+  Exploits Kerberos Constrained Delegation misconfigurations in Active Directory
+  using Impacket's findDelegation.py and getST.py (or Rubeus/Kekeo on Windows) to
+  abuse S4U2Self and S4U2Proxy and impersonate privileged users. Use during
+  authorized Active Directory penetration tests or red-team engagements for lateral
+  movement and privilege escalation after finding an account trusted for constrained
+  delegation.
 domain: cybersecurity
 subdomain: red-teaming
 tags: