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-broken-function-level-authorization/SKILL.md

@@ -1,14 +1,11 @@
 ---
 name: exploiting-broken-function-level-authorization
-description: 'Tests APIs for Broken Function Level Authorization (BFLA) vulnerabilities
-  where regular users can invoke administrative functions or access privileged API
-  endpoints by directly calling them. The tester identifies admin and privileged endpoints,
-  then attempts to access them with regular user credentials by manipulating HTTP
-  methods, URL paths, and request parameters. Maps to OWASP API5:2023 Broken Function
-  Level Authorization. Activates for requests involving BFLA testing, admin endpoint
-  bypass, function-level access control testing, or API privilege escalation.
-
-  '
+description: >-
+  Tests APIs for Broken Function Level Authorization (OWASP API5:2023) by identifying
+  admin and privileged endpoints, then reaching them with regular-user credentials
+  via HTTP method switching, URL path manipulation, and parameter tampering. Use
+  when testing whether low-privilege users can invoke admin API functions or
+  otherwise escalate privileges via function-level access control gaps.
 domain: cybersecurity
 subdomain: api-security
 tags: