Authoritative MITRE ATT&CK (Enterprise) technique lookup. Pass id (e.g. T1059 or sub-technique T1059.001) for the canonical technique — name, tactics (kill-chain phases), description, platforms, sub-technique flag + parent, mitigations, and detection guidance — or query for a keyword search returning ranked techniques. Bundled current ATT&CK matrix (~700 techniques), zero external calls. Agents cite T-numbers and tactic names that must be exact; this returns version-pinned, citeable data instead of hallucinated IDs. For threat modeling, detection engineering, and report enrichment.