How to get consistent results across different agents

How-To Agent workflows Intermediate 1041009HOWTO-1041009

HOWTO-1041009Agent workflowsIntermediate

This guide shows you how to get more consistent results when different agents work on the same spec-driven development project.

Different agents have different models, interfaces, and plugin systems. SpecDD does not make them identical. It gives them the same local contracts so their plans and changes can be compared against one source of truth.

Short answer

Keep project context in .sdd specs and bootstrap files, open the same selected content root in each agent, verify that each agent can explain the same spec, use the same short task prompt, and review every plan and diff against the same SpecDD contract.

When to use this guide

Use this guide when:

one team member uses Claude Code and another uses Codex
Copilot, Cursor, Windsurf, Gemini CLI, or OpenCode produces different plans for the same task
agents behave differently after setup
a reviewer wants a stable basis for accepting or rejecting agent output
you are switching agents during an active project

Steps

1. Put durable rules in repository files

The common context should be:

AGENTS.md
.specdd/
  bootstrap.md
  bootstrap.project.md
<root-name>.sdd
local .sdd specs

Avoid tool-specific memory as the only place a rule exists. If Claude Code knows a boundary because of chat history but Codex does not, the rule belongs in a spec or bootstrap file.

2. Use the same selected content root

Each agent should open the same project root or configured SpecDD content root.

This matters because SpecDD uses the selected content root for:

/ path resolution
root spec naming
spec indexing
inherited context
related-spec lookup

Opening a nested package as a separate root can produce a different spec chain.

3. Verify each agent with the same requests

Use the same orientation request:

Orient in this SpecDD project.

Then use the same explanation request:

Explain the Itinerary spec.

Compare substance, not phrasing. The answers should agree on purpose, writable scope, required behavior, prohibited behavior, references, tasks, and checks.

4. Use the same task prompt

Prompt each agent with the same work:

Plan the Itinerary validation change.

This makes differences visible. If one agent proposes a local validation change and another proposes a trip-wide refactor, review both against the spec and reject the overbroad plan.

5. Keep setup paths current

Use the documented setup path for each agent:

dedicated plugins for agents that have a SpecDD plugin
universal Agent Skills for compatible clients
file-aware setup for agents that can read project files but do not support skills

After setup, verify behavior. A successful install command is not enough if the agent never uses the local specs.

6. Review plans with one checklist

For every agent, ask:

did it find the same target spec?
did it propose only authorized files?
did it preserve inherited constraints?
did it avoid Must not and Forbids?
did it name checks tied to Done when or scenarios?
did it report ambiguity?

This normalizes review even when agent responses look different.

7. Feed approved new context back into specs

When one agent discovers missing context, update the spec before asking another agent to continue.

Use:

Propose an Itinerary spec update for the missing duplicate-place rule.

After review:

Update the Itinerary spec with the approved duplicate-place rule.

Now every agent can use the same durable context.

Common mistakes

Comparing agents after giving them different prompts.
Letting one agent rely on chat history while another relies on specs.
Opening different roots and then blaming the agent for different context.
Treating plugin installation as proof of spec-aware behavior.
Accepting a result because it is useful, even though it violated the local spec.

How to verify the result

You are getting consistent cross-agent results when:

each agent explains the same spec in compatible terms
planning prompts produce similar scope and checks
differences are resolved by the spec, not by preference
newly discovered rules are added to specs before reuse
reviewers use the same authority checklist for every agent

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