Agent Messaging

Overview

Defective inter-agent communication is the root cause of most multi-agent breakdowns: bloated context drowns focus, imprecise prompts yield incorrect results, and sloppy handoffs lose critical data.

Core principle: Supply agents with exactly the context they require — nothing more, nothing less. Structure every message for the recipient, not the sender.

The Prime Directive

NO AGENT DISPATCH WITHOUT A STRUCTURED BRIEF

If you have not organized the context, the agent will burn tokens deciphering your intent.

When to Use

Apply to:

Composing prompts for subagents (Agent tool dispatches)
Sending messages to team members (SendMessage)
Structuring reports back to callers or team leads
Handing off work between agents (implementer to reviewer, researcher to lead)
Deciding what context to include or exclude

Complements:

godmode:delegated-execution — Prompt design for implementer/reviewer subagents
godmode:parallel-execution — Prompt design for concurrent investigations
godmode:team-orchestration — Message design for team coordination

The Entry Protocol

BEFORE dispatching any agent or sending any message:

1. RECIPIENT: Who receives this? (subagent, teammate, team lead)
2. OBJECTIVE: What must they DO? (implement, investigate, review, report)
3. CONTEXT: What must they KNOW? (only what is relevant to their task)
4. DELIVERABLE: What must they RETURN? (format, content, detail level)
5. CONSTRAINTS: What must they NOT do? (scope limits, file restrictions)

Skip any step = unfocused agent, wasted tokens

Subagent Prompt Design

The Lean Context Principle

Subagents get distracted by irrelevant context. More context is not better context.

digraph context_decision {
    "Task follows existing pattern?" [shape=diamond];
    "Task depends on other tasks?" [shape=diamond];
    "Lean context" [shape=box style=filled fillcolor=lightgreen];
    "Full context" [shape=box];

    "Task follows existing pattern?" -> "Lean context" [label="yes - supply pattern ref"];
    "Task follows existing pattern?" -> "Task depends on other tasks?" [label="no"];
    "Task depends on other tasks?" -> "Full context" [label="yes"];
    "Task depends on other tasks?" -> "Lean context" [label="no - standalone"];
}

Lean context (default for independent tasks):

You are implementing: [1-2 sentence description]

File to modify: [exact path]
Pattern to follow: [reference to existing function/test]
What to implement: [specific requirement]
Verification: [exact command to run]

Full context (for dependent or complex tasks):

You are implementing Task N: [task name]

## Task Description
[FULL TEXT of task - paste it, do not make the subagent read a file]

## Context
[Where this fits, what preceded it, architectural decisions]

Never make a subagent read a plan file. Paste the relevant content directly. Reading files wastes tokens and attention on irrelevant sections.

Subagent Brief Template

Every subagent brief should contain these sections:

Section	Purpose	Required
Role	What the agent is doing	Yes
Task	Specific work to perform	Yes
Context	Only what is needed to understand the task	Yes
Files	Exact paths to work with	Yes
Constraints	What NOT to do, scope boundaries	Yes
Verification	How to confirm success	Yes
Deliverable format	What to report back	Yes
Questions	Permission to ask before starting	Recommended

Effective vs Ineffective Briefs

Ineffective — too vague, no structure:

Fix the tests in the auth module. They're failing.

Ineffective — too much context:

[Paste entire 500-line plan file]
Your task is Task 7, which is about auth tests.

Effective — structured and focused:

You are resolving 3 failing tests in src/auth/session.test.ts.

Failures:
1. "should reject expired sessions" - expects 401, gets 200
2. "should renew valid sessions" - timeout after 5s
3. "should handle concurrent sessions" - race condition

Context: Session management was refactored in commit def456.
The validateSession() function now returns a Promise instead of sync.

Files:
- Fix: src/auth/session.test.ts
- Reference: src/auth/session-manager.ts (the refactored code)
- Do NOT modify: src/auth/session.ts (production code is correct)

Verification: npm test -- --testPathPattern=session.test

Report: Root cause per test, what you changed, test results.

Team Message Design

Peer-to-Peer Messages

Use SendMessage with type "message" for direct coordination.

Structure messages as:

[WHAT] - One line summary of the point
[DETAIL] - Supporting information (if needed)
[ACTION] - What you need from the recipient (if anything)

Effective:

SendMessage -> backend teammate:
"The profile API needs a PUT /profile/preferences endpoint.
Frontend needs to update preferences without replacing the full profile.
Can you add this to the contract before implementing?"

Ineffective:

SendMessage -> backend teammate:
"Hey, I was working on the frontend and I noticed we need
some changes. The profile page has this preferences feature where
users can update without replacing everything and I think we need
a new endpoint for that. What do you think? Also I noticed..."

Broadcast vs Direct Message

digraph message_type {
    "Who needs this information?" [shape=diamond];
    "Entire team?" [shape=diamond];
    "broadcast (expensive)" [shape=box];
    "SendMessage to specific teammate" [shape=box style=filled fillcolor=lightgreen];

    "Who needs this information?" -> "Entire team?";
    "Entire team?" -> "broadcast (expensive)" [label="yes - convention change, critical blocker"];
    "Entire team?" -> "SendMessage to specific teammate" [label="no - most cases"];
}

Broadcast only when:

Convention or pattern change that affects every teammate
Critical blocker that halts all progress
Shared resource conflict

Direct message for everything else (status reports, questions, findings, coordination).

Reporting to Team Lead

When completing a task, report:

COMPLETED: [task name]
RESULT: [one-line summary]
FILES CHANGED: [list]
FINDINGS: [anything the lead or other teammates should know]
CONCERNS: [anything that might affect other tasks]

Handoff Formats

Implementer to Reviewer

## What Was Built
[Summary - what changed and why]

## Files Changed
[Exact paths, one per line]

## Test Results
[Pass/fail counts, any notable results]

## Self-Review Notes
[Issues found and resolved during self-review]
[Remaining concerns]

## Verification Command
[Exact command to run]

Reviewer to Implementer (Fix Request)

## Issues Identified
[List each issue with file:line reference]

## Priority
- Blocking: [must resolve before approval]
- Important: [should resolve]
- Suggestion: [consider for improvement]

## Scope Boundaries
[Do not refactor while fixing — stay focused]

Investigator to Lead (Debug/Research)

## Hypothesis Under Test
[What was being investigated]

## Evidence
- Supporting: [evidence favoring the hypothesis]
- Contradicting: [evidence against the hypothesis]

## Confidence
[High/Medium/Low with reasoning]

## Recommendation
[Next steps based on findings]

## Cross-Cutting Discoveries
[Anything that affects other investigations]

Context Management

What to Include

Exact file paths (always absolute, never approximate)
Error messages verbatim (do not paraphrase)
Relevant code snippets (not entire files)
Specific line numbers for references
Verification commands ready to copy-paste
Dependencies and prerequisites

What to Exclude

Complete plan files (paste only the relevant task)
Completed task details (unless they are dependencies)
Project history irrelevant to the task
Alternative approaches that were rejected
Verbose explanations of obvious patterns

The Context Budget Guideline

Agent Type	Target Context	Rationale
Implementer	Task + pattern + files	Focus on building
Reviewer	Spec + diff + checklist	Focus on verifying
Investigator	Hypothesis + evidence locations	Focus on discovering
Teammate message	Action needed + minimal context	Respect their context window

Error Escalation

When an agent encounters an unresolvable problem:

digraph escalation {
    "Agent hits obstacle" [shape=box];
    "Can resolve independently?" [shape=diamond];
    "Resolve it" [shape=box];
    "Affects only own task?" [shape=diamond];
    "Report to lead at task completion" [shape=box];
    "Message lead immediately" [shape=box];
    "Affects other teammates?" [shape=diamond];
    "Message affected teammates" [shape=box];

    "Agent hits obstacle" -> "Can resolve independently?";
    "Can resolve independently?" -> "Resolve it" [label="yes"];
    "Can resolve independently?" -> "Affects only own task?" [label="no"];
    "Affects only own task?" -> "Report to lead at task completion" [label="yes"];
    "Affects only own task?" -> "Affects other teammates?" [label="no - blocks others"];
    "Affects other teammates?" -> "Message affected teammates" [label="yes"];
    "Affects other teammates?" -> "Message lead immediately" [label="no - requires lead decision"];
}

Escalation message format:

BLOCKED: [what is blocked]
CAUSE: [why it is blocked]
ATTEMPTED: [what was tried]
NEED: [what would unblock - decision, information, or fix]

Cognitive Traps

Rationalization	Truth
"More context is always helpful"	More context = more distraction. Lean context produces better results for independent tasks.
"They can figure out what's relevant"	Agents waste tokens parsing irrelevant content. Curate context for them.
"Just read the plan file"	Plan files contain all tasks. The agent gets distracted by other tasks. Paste only the relevant portion.
"I'll explain informally, no structure needed"	Unstructured prompts produce unstructured results. Use the template.
"Short messages seem curt"	Concise messages respect the recipient's context window.
"I'll report everything I found"	Report what is actionable. Filter noise before sending.

Guardrails

Prohibited:

Making subagents read plan files (paste content instead)
Sending unstructured prompts ("fix the tests")
Including irrelevant context ("here's the full history...")
Using broadcast for routine updates
Omitting the deliverable format section (agents will not know what to report)
Escalating without stating what was already attempted

Mandatory:

Structure every prompt with role, task, context, constraints, deliverable
Paste content directly instead of referencing files
Include verification commands in implementation prompts
Use direct messages over broadcast
Include file paths in every handoff
Report cross-cutting discoveries to affected parties

Integration

Consumed by:

godmode:delegated-execution — Implementer and reviewer prompts
godmode:parallel-execution — Concurrent agent prompts
godmode:team-orchestration — Team communication patterns