Check gh and MCP publishing before it posts

Goal. A gh pr comment, a gh issue create, or an MCP call that posts a page is checked with the text in hand, and denied when the text carries an error.

Precondition. Claude Code 2.1.85 or newer for the gh command filter. Older versions work; the hook then runs on every Bash command, with the same results.

Steps

1. Edit .just-say-so.json:

   { "publish": { "gh": true, "mcp": ["mcp__confluence__*", "mcp__jira__*"] } }

   Name the MCP tools by pattern, with * wildcards. publish.mode is already block.

2. Decide what happens to a value the checker cannot read before the call, such as a $(...) substitution or a heredoc. The default, ask, prompts you. Set "unresolved": "deny" for a pipeline that must never guess, or "allow" to let those through.

3. Confirm with the doctor: the targets line reads publish block, gh, mcp 2 pattern(s), artifact.

Narrowing rules per field

Each value lints as its own fragment, named gh.<subcommand>.<field>.publish or mcp.<server>.<tool>.<field>.publish. A section in .vale.ini narrows one:

[gh.*.title.publish]
ai-tells.SentenceLength = NO

The known gaps are listed in Checking published text.