harness-tools
Skill5 starsChanged 10 days agoMITView on GitHub
The tool each agent harness (Claude Code, Codex, Grok, agy) uses to start, follow up with, or stop a sub-agent, and to ask the user a structured question. Use when a skill names one of these moves and points here, or when you are not sure which tool your harness has for it.
In this repository57 other files it gives its agents.
- AGENTS.mdAGENTS.md
- CLAUDE.mdCLAUDE.md
- architecture-satisfactionSkill
- autopilotSkill
- browser-testSkill
- chatter-scoutSkill
- closeoutSkill
- codebase-designSkill
- code-reviewSkill
- code-smells-auditSkill
- commitSkill
- dependency-auditSkill
- diagnosing-bugsSkill
- domain-modelingSkill
- fix-ci-failuresSkill
- fix-github-issuesSkill
- fix-nightwatch-issuesSkill
- fix-posthog-issuesSkill
- grillingSkill
- grill-meSkill
- grill-with-docsSkill
- handoffSkill
- housekeeperSkill
- implementSkill
- implement-specSkill
- improve-codebase-architectureSkill
- laravel-herd-worktreesSkill
- panelSkill
- prototypeSkill
- prSkill
- prune-testsSkill
- releaseSkill
- repository-cleanupSkill
- researchSkill
- resolve-review-commentsSkill
- resolving-merge-conflictsSkill
- retroSkill
- run-afterSkill
- scratch-cleanupSkill
- scratch-statusSkill
- setupSkill
- sweepSkill
- tddSkill
- teachSkill
- to-questionnaireSkill
- to-specSkill
- to-ticketsSkill
- triage-github-prSkill
- triageSkill
- ui-designSkill
- upgrade-planSkill
- verifySkill
- wait-whatSkill
- wayfinderSkill
- which-skillSkill
- wizardSkill
- writing-for-agentsSkill
The file
We split this skill into the rules it gives an agent
2 rules. About 0 are common, 2 are distinctive, and 0 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈2
Distinctive · estimate
This author's own choices. Worth a look.
0
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Distinctive: line 21
Start one or more sub-agents and use every result before you go on.
- Distinctive: line 34
Start sub-agents and keep working on something else.
≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
Harness Tools
Skills name a move (dispatch and wait, dispatch in the background, follow up, stop, structured question) and point here for the tool. Find your harness's row, use that tool with the skill's own content (the brief, the agent type, the options), and use the fallback when the tool is not in your tool list. A harness with no row here: use its own tool for the move if it has one, otherwise the fallback. The fallback is always a complete path.
Verified against: Codex CLI 0.166's model-visible tools; Grok's live tool schema and its logged calls (its parameter is background, though the docs say run_in_background); agy 1.4.12's live tool schema, checked against its logged calls.
Every sub-agent
- Brief it in full. A sub-agent starts with none of your conversation: a Grok child starts a new conversation, Codex's
fork_turns: "none"passes no history, and an agy sub-agent gets only itsPrompt. Put every path, ref, and rule it needs in the brief. - Typed agents. A skill may name a typed agent,
leek-skills:<name>, often in its Claude Code clause. Claude Code and Grok both load these from this plugin'sagents/when the plugin is installed, so in Grok pass that same name assubagent_type. Codex and agy never loadagents/, and neither does a Claude Code or Grok install fromnpx skillsalone. There, start a general sub-agent with the same brief, and hold it to the typed agent's rules (read-only, output shape) through the brief. - Model tier. Where the skill asks for a cheaper or stronger model: Claude Code's
model(haiku,sonnet,opus), Codex'smodel(omit it to inherit), agy'sModel(flash_liteorflashcheaper,prostronger,inheritthe default). Grok: inherit.
Dispatch and wait
Start one or more sub-agents and use every result before you go on. For several, start them all in one message first, then wait for all of them.
| Harness | Tool |
| Claude Code | Agent (foreground) |
| Codex | spawn_agent with a task_name, the brief as message, and fork_turns: "none"; then call wait_agent (raise timeout_ms, up to 3600000) until each one's final answer has arrived. wait_agent reports which agents have updates; the answers arrive as messages. |
| Grok | spawn_subagent with background: false |
| agy | invoke_subagent with TypeName: "self", a 2–5 word Role, the brief as Prompt. agy has no foreground form: each sub-agent sends you a message when it finishes, so end the turn and let those messages wake you, and do nothing else the step depends on until every one has arrived. Never poll. TypeName: "research" also exists; its tool set is unverified, so a read-only brief still says read-only. |
Fallback: do the work inline, and say so.
Dispatch in the background
Start sub-agents and keep working on something else; collect each result when it lands. Keep each returned name or id against the skill's label for it, so you can follow up or stop it.
| Harness | Tool |
| Claude Code | Agent with run_in_background: true where offered (sub-agents may already default to the background), and a name. Each completion notification wakes you; end the turn while you wait, and never poll. |
| Codex | spawn_agent as above, keeping each task_name. Do the other work in the same turn, then wait_agent for the results. Do not end the turn while they run. |
| Grok | spawn_subagent (background defaults to true), keeping each id. The harness notifies you when a child finishes; then read its result with get_command_or_subagent_output. Never poll. |
| agy | invoke_subagent as above, keeping the conversationId it returns. It sends you a message when it finishes; never poll. |
Fallback: run them inline one after another.
A sub-agent's handle dies at /clear, at session end, and at compaction. In anything durable (tickets, comments, hand-off text), refer to its output by file path, never by task id.
Follow up
Send more work to a sub-agent that is running or has finished, so it keeps its context.
| Harness | Tool |
| Claude Code | SendMessage to its name |
| Codex | followup_task to its task_name (starts a turn if it is idle), or send_message (no new turn) |
| Grok | send_subagent_message, only when active agent messages are on (GROK_ACTIVE_AGENT_MESSAGES or [features] active_agent_messages); otherwise wait for it to finish and continue it with resume_from |
| agy | send_message with Recipient (its conversationId) and Message |
Fallback: brief a fresh sub-agent with everything the follow-up needs (paths, the finding, the failure output).
Stop
| Harness | Tool |
| Claude Code | TaskStop with its name or task id |
| Codex | interrupt_agent (it stops the current turn; the agent stays available for follow-ups) |
| Grok | kill_command_or_subagent |
| agy | manage_subagents with Action: "kill" and its ConversationIds. This also kills its own sub-agents and deletes any branched workspace. |
Fallback: leave it running and say so in the report.
Structured question
A click-to-answer question: the recommended option first and marked as recommended, real options only, and a free-text Other that the harness adds. When the skill asks for more questions or options than your tool takes, split them over further calls; when it asks for multiSelect and your tool has none, ask that question in chat.
| Harness | Tool | Shape |
| Claude Code | AskUserQuestion | Up to 4 questions per call, 2–4 options each. Each question has a header (12 characters at most); each option a label and a description, and may have a preview (single-select only). multiSelect: true for a pick-several question. |
| Grok | ask_user_question | Like Claude Code, but the pick-several flag is multi_select and there is no header. Options take label, description, and preview. |
| Codex | request_user_input, only when it is in your tool list for this turn (Plan mode) | 1–3 questions, each with a header (12 characters at most), an id, and 2–3 single-select options of label and description. No preview and no multi-select: put a short snippet in the option description, or show side-by-side artifacts in chat first. |
| agy | ask_question | questions of {question, options, is_multi_select}. Options are plain strings with no description or preview: put each option's trade-off in its text, start the recommended one with (Recommended), and show any preview in chat first. Ask a trivial yes/no in plain text instead. |
Fallback: the same shape in chat: the question, the numbered options with the recommendation first, then wait for the answer.
Workspaces
A skill that makes its own git worktree passes that path in the brief. In agy, keep invoke_subagent's Workspace at its default (inherit), so the path in the brief is the path the sub-agent sees.
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.