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-aws-with-pacu/SKILL.md

@@ -1,6 +1,12 @@
 ---
 name: exploiting-aws-with-pacu
-description: Use Pacu modules for AWS privilege escalation, persistence, and backdooring.
+description: >-
+  Runs the Pacu AWS exploitation framework end-to-end — session and credential setup,
+  IAM enumeration, automated privilege-escalation scanning via iam__privesc_scan,
+  and persistence/backdooring modules like iam__backdoor_users_keys. Use for
+  authorized AWS penetration tests or red-team engagements, assessing blast radius
+  from a compromised IAM credential, or generating attacker telemetry for purple-team
+  detection testing.
 domain: cybersecurity
 subdomain: cloud-security
 tags: