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/analyzing-malware-behavior-with-cuckoo-sandbox/SKILL.md

@@ -1,10 +1,11 @@
 ---
 name: analyzing-malware-behavior-with-cuckoo-sandbox
-description: 'Executes malware samples in Cuckoo Sandbox to observe runtime behavior
-  including process creation, file system modifications, registry changes, network
-  communications, and API calls. Generates comprehensive behavioral reports for malware
-  classification and IOC extraction. Activates for requests involving dynamic malware
-  analysis, sandbox detonation, behavioral analysis, or automated malware execution.
+description: 'Detonate malware samples in Cuckoo Sandbox to observe runtime behavior
+  — process creation, file system and registry changes, network communications,
+  and API calls — and generate behavioral reports for classification and IOC extraction.
+  Use when a sample has passed static triage and needs dynamic/behavioral analysis,
+  when mapping a full infection chain, or when building YARA/behavioral signatures
+  from observed sandbox activity.
 
   '
 domain: cybersecurity