Conciseness

The body is lean and assumes Claude's competence: each section states only the non-obvious rule ('Do not use the `message` tool for cross-room sends', 'remove all Matrix IDs from the message in your head', 'If two rounds of replies produce no new task, question, or decision, stop replying') with no padding or explanation of concepts Claude already knows.

Actionability

Guidance is concrete and executable — exact mention formats like '@coordinator:domain TASK_COMPLETED: <summary>', an explicit mental filter ('remove all Matrix IDs... send only if the remaining text contains a concrete completion, blocker, question...'), and a concrete stop rule — but it is instruction-only with no command/code, so it falls just short of fully copy-paste-ready 5 for an instruction skill.

Workflow Clarity

The mention decision flow is clearly sequenced: enumerate valid mention reasons, exclude low-information cases, apply the exception, then apply the remove-Matrix-IDs filter and the two-round loop safeguard as a checkpoint. It is a decision/gating workflow rather than a destructive batch operation, so the destructive-cap does not apply; it lacks only an explicit validate-then-retry feedback loop to reach 5.

Progressive Disclosure

This is a short, self-contained skill (under 50 lines, single task) with no bundle files in references/scripts/assets, organized into clear well-labeled sections (Routing, Coordinator Identity, @Mention Rules, History Context, Loop Safeguard); per the simple-skills guidance this warrants a 5 with no external references needed.

Specificity

Names the domain (communication routing/@mentions) and lists several concrete actions — 'sending @mentions, deciding whether to reply, TASK_COMPLETED, BLOCKED, QUESTION, direct answers, loop prevention, suppressing low-information acknowledgements' — covering multiple specific behaviors with only minor gaps.

Completeness

Explicitly provides a 'when' trigger via 'Use before sending @mentions, deciding whether to reply...' and the enumerated list conveys the 'what' (which communication acts the skill governs), but the 'what' is implicit through the trigger list rather than stated as a standalone capability, so it is not a fully explicit 5.

Trigger Term Quality

Includes natural trigger terms a user would voice ('reply', '@mentions', 'BLOCKED', 'QUESTION', 'TASK_COMPLETED') and the 'Use before...' framing, but lacks common synonyms or phrasings a user might naturally say, leaving a few natural terms missing.

Distinctiveness Conflict Risk

The narrow trigger set (mentions, TASK_COMPLETED/BLOCKED/QUESTION signals, loop prevention) carves a fairly distinct niche, though 'deciding whether to reply' and 'loop prevention' are broad enough to create minor overlap with general conversation/coordination skills.