cost-tier-routing

name

cost-tier-routing

description

Use BEFORE doing direct file search, bulk reads, data import/export, or routine coding edits in the main conversation. Routes work to the cheapest model that can do it correctly — haiku for search/IO, sonnet for coding, opus for orchestration/architecture. Triggers when about to call Read on >2 files, Grep/Glob across the repo, batch CSV/JSON transforms, or any "where is X / list all Y / count Z" question. Also triggers when the orchestrator (you, on opus) is about to write straightforward code that a sonnet subagent could handle.

Cost-Tier Routing

Opus tokens cost ~5x sonnet and ~25x haiku. Doing Read and Grep on opus is lighting money on fire. This skill is the discipline for routing every action to the cheapest model that can do it correctly.

This skill requires three companion agents — haiku-scout, haiku-importer, and sonnet-coder — installed in ~/.claude/agents/. See this package's README.md for the two-step install. The skill is inert without the agents because the model: pin lives in the agent files, not here.

The rule

Before any of these actions in the main (opus) context, dispatch to a subagent instead:

Action	Route to	Why
Read more than 1–2 files in a row	haiku-scout	Bulk reads burn opus context
Grep / Glob across the repo	haiku-scout	Mechanical lookup
"Where is X defined?" / "What references Y?"	haiku-scout	Pure search
Count LOC, list files, read a config	haiku-scout	Trivial IO
Convert/parse/split/merge data files	haiku-importer	Mechanical transform
Download + parse a fixture or seed file	haiku-importer	Mechanical IO
Write code at a known location with a known design	sonnet-coder	Implementation, not design
Refactor a function with clear constraints	sonnet-coder	Bounded edit
Run tests / typecheck after an edit	sonnet-coder (bundle with the edit)	Don't bounce back to opus mid-task

Keep on opus (the orchestrator):

• Architectural decisions, tradeoff analysis
• Reading subagent reports and deciding the next step
• Synthesis across multiple subagent outputs
• User-facing explanations and recommendations

The dispatch pattern

When you (opus) recognize a routable task:

1. Phrase the brief like a closed ticket, not an open question. Include: exact files/dirs, exact output format, exact verification command.
2. Call Agent with the right subagent_type — haiku-scout, haiku-importer, or sonnet-coder. The model is pinned in the agent file; do not override unless you have a specific reason.
3. Read the report, don't redo the work. If the subagent missed something, dispatch again with a sharpened brief — don't bail out and do it yourself on opus.
4. Parallel where independent. If you need three unrelated searches, fire three haiku-scout calls in one message.

When to NOT route

• A single one-line Read of a file you're about to edit yourself — just read it.
• A trivial Grep (one pattern, one directory) you're about to act on immediately — just grep.
• Tasks already inside a subagent — subagents do their own work, they don't recursively dispatch the same tier.
• When the user explicitly asked you to do it directly.

The threshold is roughly: if the action will take >3 tool calls or >1000 tokens of file content, route it.

Red flags (you're about to waste money)

• "Let me read these 8 files to understand the structure" → STOP, dispatch haiku-scout with a structural-survey brief.
• "Let me grep for all usages, then read each one" → STOP, dispatch haiku-scout to return paths+excerpts in one shot.
• "I'll just write this small fix" while sitting on opus → consider sonnet-coder if it involves >1 file or any test run.
• "Let me convert this CSV real quick" → STOP, dispatch haiku-importer.

Escalation back to opus

Subagents are instructed to escalate when they hit reasoning work. When you get a report ending in ESCALATE: ..., that's the signal that the next step is genuinely yours. Don't push it back down — handle it on opus and re-dispatch a sharpened mechanical task if needed.

Self-check

Before every tool call in the main context, ask: Could a cheaper model do this exact action with the same correctness? If yes, dispatch. If no, proceed.