diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index e469024..42f068a 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -5,9 +5,10 @@
 	},
 	"features": {
 		"ghcr.io/va-h/devcontainers-features/uv:1": {},
-		"ghcr.io/prulloac/devcontainer-features/ollama:1": {}
+		"ghcr.io/prulloac/devcontainer-features/ollama:1": {},
+		"ghcr.io/devcontainers-extra/features/mise:1": {}
 	},
-	"postCreateCommand": "uv sync --dev && uv run prek install",
+	"postCreateCommand": "uv sync --dev && mise install && uv run prek install",
 	"customizations": {
 		"vscode": {
 			"extensions": [
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 0c0bee3..5464da0 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -255,13 +255,15 @@ jobs:
             echo "| coverage (≥80%) | ${{ needs.test.outputs.coverage_outcome == 'success' && '✅ Passed' || '❌ Failed' }} (${{ needs.test.outputs.coverage_pct }}%) |"
             echo
 
+            contributing_url="https://github.com/${{ github.repository }}/blob/main/CONTRIBUTING.md"
+
             if [ "${{ needs.lint.outputs.prek_outcome }}" != "success" ]; then
               echo "<details><summary>prek output</summary>"
               echo
               echo '```'
               echo "$PREK_OUTPUT"
               echo '```'
-              echo "Run \`uv run prek run --all-files\` locally to reproduce and fix."
+              echo "Run \`uv run prek run --all-files\` locally to reproduce and fix. See [Pre-commit Hooks (prek)]($contributing_url#pre-commit-hooks-prek) in CONTRIBUTING.md."
               echo "</details>"
             fi
             if [ "${{ needs.typecheck.outputs.mypy_outcome }}" != "success" ]; then
@@ -270,7 +272,7 @@ jobs:
               echo '```'
               echo "$MYPY_OUTPUT"
               echo '```'
-              echo "Run \`uv run mypy tapio\` locally to reproduce and fix."
+              echo "Run \`uv run mypy tapio\` locally to reproduce and fix. See [Type Checking]($contributing_url#type-checking) in CONTRIBUTING.md."
               echo "</details>"
             fi
             if [ "${{ needs.typecheck.outputs.pyrefly_outcome }}" != "success" ]; then
@@ -279,7 +281,7 @@ jobs:
               echo '```'
               echo "$PYREFLY_OUTPUT"
               echo '```'
-              echo "Run \`uv run pyrefly check\` locally to reproduce and fix."
+              echo "Run \`uv run pyrefly check\` locally to reproduce and fix. See [Type Checking]($contributing_url#type-checking) in CONTRIBUTING.md."
               echo "</details>"
             fi
             if [ "${{ needs.test.outputs.pytest_outcome }}" != "success" ]; then
@@ -288,9 +290,12 @@ jobs:
               echo '```'
               echo "$PYTEST_OUTPUT"
               echo '```'
-              echo "Run \`uv run pytest\` locally to reproduce and fix."
+              echo "Run \`uv run pytest\` locally to reproduce and fix. See [Running Tests]($contributing_url#running-tests) in CONTRIBUTING.md."
               echo "</details>"
             fi
+            if [ "${{ needs.test.outputs.coverage_outcome }}" != "success" ]; then
+              echo "See [Code Coverage]($contributing_url#code-coverage) in CONTRIBUTING.md for how to check coverage locally."
+            fi
           } >> "$GITHUB_STEP_SUMMARY"
 
       # Posts a sticky comment directly in the PR conversation (not just the Summary
@@ -319,14 +324,33 @@ jobs:
             const coveragePct = '${{ needs.test.outputs.coverage_pct }}' || 'unknown';
             const passed = '${{ needs.test.outputs.coverage_outcome }}' === 'success';
             const marker = '<!-- tapio-coverage-report -->';
+            const contributingUrl = `https://github.com/${context.repo.owner}/${context.repo.repo}/blob/main/CONTRIBUTING.md`;
+            const author = context.payload.pull_request.user.login;
 
             const failures = [
-              { outcome: '${{ needs.lint.outputs.prek_outcome }}', name: 'prek', output: process.env.PREK_OUTPUT, fix: 'uv run prek run --all-files' },
-              { outcome: '${{ needs.typecheck.outputs.mypy_outcome }}', name: 'mypy', output: process.env.MYPY_OUTPUT, fix: 'uv run mypy tapio' },
-              { outcome: '${{ needs.typecheck.outputs.pyrefly_outcome }}', name: 'pyrefly', output: process.env.PYREFLY_OUTPUT, fix: 'uv run pyrefly check' },
-              { outcome: '${{ needs.test.outputs.pytest_outcome }}', name: 'pytest', output: process.env.PYTEST_OUTPUT, fix: 'uv run pytest' },
+              { outcome: '${{ needs.lint.outputs.prek_outcome }}', name: 'prek', label: 'Lint (prek)', output: process.env.PREK_OUTPUT, fix: 'uv run prek run --all-files', docs: `${contributingUrl}#pre-commit-hooks-prek`, docsLabel: 'Pre-commit Hooks (prek)' },
+              { outcome: '${{ needs.typecheck.outputs.mypy_outcome }}', name: 'mypy', label: 'Type Checking (mypy)', output: process.env.MYPY_OUTPUT, fix: 'uv run mypy tapio', docs: `${contributingUrl}#type-checking`, docsLabel: 'Type Checking' },
+              { outcome: '${{ needs.typecheck.outputs.pyrefly_outcome }}', name: 'pyrefly', label: 'Type Checking (pyrefly)', output: process.env.PYREFLY_OUTPUT, fix: 'uv run pyrefly check', docs: `${contributingUrl}#type-checking`, docsLabel: 'Type Checking' },
+              { outcome: '${{ needs.test.outputs.pytest_outcome }}', name: 'pytest', label: 'Tests (pytest)', output: process.env.PYTEST_OUTPUT, fix: 'uv run pytest', docs: `${contributingUrl}#running-tests`, docsLabel: 'Running Tests' },
             ].filter((check) => check.outcome !== 'success');
 
+            const failedLabels = failures.map((check) => check.label);
+            if (!passed) {
+              failedLabels.push('Coverage');
+            }
+
+            // Mentioning the author only happens once per PR in practice: GitHub notifies
+            // on comment creation, and this step updates the same sticky comment on
+            // reruns rather than creating a new one, so re-running CI doesn't re-ping them.
+            const greeting = failedLabels.length
+              ? [
+                  `👋 Hi @${author}, thanks for the pull request! Before this can be merged, please address: **${failedLabels.join(', ')}**.`,
+                  '',
+                  'Details and local reproduction commands are below, with links to the relevant CONTRIBUTING.md section for each.',
+                  '',
+                ]
+              : [];
+
             const failuresSection = failures.length
               ? [
                   '## CI Failures',
@@ -338,7 +362,7 @@ jobs:
                     check.output || '(no output captured)',
                     '```',
                     '',
-                    `Run \`${check.fix}\` locally to reproduce and fix.`,
+                    `Run \`${check.fix}\` locally to reproduce and fix. See [${check.docsLabel}](${check.docs}) in CONTRIBUTING.md.`,
                     '</details>',
                     '',
                   ]),
@@ -347,6 +371,7 @@ jobs:
 
             const body = [
               marker,
+              ...greeting,
               ...failuresSection,
               '## Test Coverage Report',
               '',
@@ -354,7 +379,7 @@ jobs:
               '',
               passed
                 ? 'Coverage meets the project threshold. 🎉'
-                : '⚠️ Coverage is below the required 80% threshold. Please add tests for the new or changed code before this pull request can be merged.',
+                : `⚠️ Coverage is below the required 80% threshold. Please add tests for the new or changed code before this pull request can be merged. See [Code Coverage](${contributingUrl}#code-coverage) in CONTRIBUTING.md.`,
             ].join('\n');
 
             // paginate() walks every page of comments, not just the first 30, so a
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 880e861..756322e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -121,8 +121,9 @@ The dev container includes:
 - Python 3.14
 - `uv` package manager
 - Ollama for local LLM inference
+- [`mise`](https://mise.jdx.dev/), which manages `actionlint` and `markdownlint-cli2` (used by two of the prek hooks below)
 - All required VS Code extensions (Python, Ruff, GitHub Copilot, etc.)
-- Automatic dependency installation via `uv sync --dev`
+- Automatic dependency installation (`uv sync --dev`) and tool installation (`mise install`)
 
 ### Using GitHub Codespaces (Cloud Alternative)
 
@@ -150,9 +151,9 @@ For a completely cloud-based development environment that requires no local setu
 
 The Codespace includes the same development environment as the local dev container:
 
-- Python 3.14, `uv` package manager, and Ollama
+- Python 3.14, `uv` package manager, Ollama, and `mise`
 - All required VS Code extensions pre-installed
-- Automatic dependency installation
+- Automatic dependency and tool installation
 
 ### Manual Setup (Alternative)
 
@@ -182,6 +183,13 @@ uv sync --dev
 1. Install Ollama for local LLM inference:
    - Follow the installation instructions at [ollama.ai](https://ollama.ai)
 
+1. Install [`mise`](https://mise.jdx.dev/), which manages the versions of `actionlint` and `markdownlint-cli2` used by two of the prek hooks below (without it, those two hooks fail with "command not found"):
+
+```bash
+curl https://mise.run | sh
+mise install   # installs the tool versions pinned in mise.toml
+```
+
 ### Installing Required Models
 
 Regardless of which setup method you chose, you'll need to install `llama3.2`, the base model this project uses for text generation:
@@ -252,7 +260,7 @@ To run all hooks against the full codebase (useful before submitting a pull requ
 uv run prek run --all-files
 ```
 
-These are the same checks enforced in CI (excluding mypy and Pyrefly, which CI runs as separate steps against the project's own virtual environment).
+These are the same checks enforced in CI (excluding mypy and Pyrefly, which CI runs as separate steps against the project's own virtual environment). Two of the hooks (`actionlint`, `markdownlint-cli2`) run through `mise exec --` and require [`mise`](https://mise.jdx.dev/) to be installed and have run `mise install` once — see [Manual Setup](#manual-setup-alternative) if you're missing it.
 
 ## Testing Guidelines