Single tool (update_slack_status) with mixed quality. Naming is action-verb based and clear. Description is detailed but exceeds optimal length (194 char baseline; this is ~320 chars including examples). Schema is present with proper types (string, long) and individual parameter descriptions. However, the description includes example values ('🏃', current time + 3600), which violates guidance against embedding examples in descriptions, LLMs tend to reuse them literally. Parameter descriptions are adequate but could be more constraint-focused. No error handling guidance, no recovery documentation, and no idempotency or confirmation pattern for a write operation. Overall functional but misses several A-grade patterns.

• Replace example values in description with formal JSON Schema constraints: add 'maxLength: 10' to statusText schema, remove 'max 10 chars' prose.
• Convert emoji guidance to a pattern constraint (e.g., pattern: '^[\p{Emoji}]$' or a description: 'Must be a single Unicode emoji character').
• Add explicit error handling guidance: 'On failure (invalid emoji, rate limit, auth error), returns error object with code and message. Retry after 60 seconds on rate_limit_exceeded.'
• Document the output schema: 'Returns {success: boolean, previous_status: string, expires_at: number (Unix epoch)} or {error: string, code: string}.'
• Add idempotency or confirmation note: 'This operation is idempotent, calling twice with the same status is safe. Consider dry-run: false parameter for confirmation pattern.'
• Remove concrete examples from the description text; move them to a separate 'examples' field in the tool definition if the framework supports it.