skilld
All skills
oaustegard avatar

/agent-routing

@576f2c8
by Oskar Austegardoaustegard/claude-skills150 stars
6

Decide which model, effort level, and cascade shape each subagent gets, and how to keep improvement loops safe (evaluator-as-selector, stop on regression). Routes on measured cost-per-completed-task rather than per-token price, because a tier's token count varies more by task shape than price varies across tiers. Covers per-model effort semantics, the concision lever, cascade preconditions, context handoff, and watching a subagent fan-out live. Use when spawning subagents via the Agent or Workflow tools, when choosing how to escalate a failed attempt, when fanning out more than a handful of agents, or when asked which model or effort a task should get. Grounded in measured calibration (references/calibration-2026-07-15.md), a 2026-08 coding-cost study, and a 2026-09 agentic-repair battery that measured the cascade rungs directly; Managed Agents API specifics are operational, not calibrated.

Ask your Agent

Use this Skill: https://skilld.dev/gh/oaustegard/claude-skills/agent-routing

This session only. Nothing lands on disk.

CHANGELOG.md

≈943 tokens on demand. Your agent reads this file only when SKILL.md points to it.

agent-routing - Changelog

All notable changes to the agent-routing skill are documented in this file. The format is based on Keep a Changelog.

[2.3.0] - 2026-09-29

Other

  • agent-routing 2.3.0: Sonnet 5.5 effort measured

[2.3.0] - 2026-09-29

Added

  • Sonnet 5.5 effort measured on the seeded-bug battery, two replicates: low 10 and 11 of 14, medium 11 and 12, high 12 and 12, against Sonnet 5 low at 9/14. low no longer switches thinking off. Sonnet 5.5 @ high matched Opus 5.5 @ high (24 of 28 each) at 0.43x the cost per completed task. Opus 5.5 emitted a third of Opus 5's output on the same tasks.

[2.2.0] - 2026-09-29

Other

  • agent-routing 2.2.0: effort channels, cache TTL, Sonnet 5.5 caveat

[2.2.0] - 2026-09-29

From the 2026-09-28 Claude Code effort experiments (muninn.austegard.com/blog/effort-levels-in-claude-code-subagents.html) and the Sonnet 5.5 release.

Added

  • Which channel sets whose effort: Workflow agent({effort}) is the only way a parent sets a subagent's effort; Agent and SendMessage have none; a resumed subagent picks up the session's /effort.
  • How to run rung 2 in Claude Code: a fresh Workflow agent one effort step up for subagents, a recommended /effort change for the main loop.
  • The cache TTL, not the effort change, is what misses: subagents cache on the 5-minute tier, the parent on the 1-hour tier.

Changed

  • Caching paragraph: an effort change keeps the cache in Claude Code (five resumes across a level change all hit), and the API's per-message effort message now covers Opus 5.5 and Sonnet 5.5. Replaces "an effort change invalidates the messages cache on every model".
  • Haiku's effort column reads n/a: the API rejects effort on Haiku 4.5 and Claude Code drops it.
  • Every Sonnet figure is labelled as Sonnet 5 data pending a re-measure on Sonnet 5.5, whose effort levels were recalibrated.

[2.1.0] - 2026-09-04

Other

  • agent-routing 2.1.0: measured cascade rungs, escalation signal, tier gap (#785)

[2.1.0] - 2026-09-03

Measured against a 14-repo seeded-bug agentic battery (~120 subagent runs; oaustegard/experiments -> temporal-routing-headroom). Nothing was retracted; the cascade section gained the numbers it was missing.

Added

  • The escalation call belongs to whoever holds the verifier, never the worker. 58 of 58 graded runs self-reported success; 44 had passed. Every failure claimed to be done.
  • Rung 2 is the same model one effort step up; a tier jump is the exception. From an identical failed attempt, sonnet @ medium and opus @ high rescued the same 4 of 5 tasks at 11,691 vs 32,504 output tokens (0.31x vs 0.76x always-opus composed).
  • A cascade can beat the frontier solo arm on correctness: 13/14 vs 10/14.
  • Caching in the cascade: caches are model-scoped with no escape hatch, so a tier jump discards rung 1's prefix; an effort change invalidates the messages cache on every model, and the per-message effort hatch is Opus 5 / Fable 5.1 / Mythos 5.1 only.
  • Informed retry means the artifacts, not the prior model's narrative: adding rung 1's stated diagnosis moved 12/15 to 13/15 on one replicate of one unstable task.
  • Concision does not reach small-output work: 2.9% on agentic repair vs 37% on generation.
  • Route up for capability, not thoroughness: opus @ high fell into the same stop-early trap as sonnet @ low on three of four tasks.
  • Seeded-bug repair in a small module is measured as not tier-separating across three probe shapes.

Changed

  • Cost-model caveat made explicit: every figure prices output tokens only.

[2.0.0] - 2026-08-18

Added

  • Add/Update skill: agent-routing (#767)

Source: SKILL.md on GitHub

Third-party checks

No alerts12d3 checks · Risk SAFE
  • Gen Agent Trust Hub12d

    The skill provides technical guidelines for routing tasks between different AI models and managing subagent orchestration. It is generally safe; however, it encourages a workflow where untrusted data, such as file scan outputs, is passed directly into subagent prompts, which creates a surface for indirect prompt injection.

  • Socket12d

    No alerts

  • Snyk12d

    Risk: LOW · No issues

Provenance

Signed by skilld at 576f2c8. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub yesterday.

Activeupdated 3 days ago

Capability

metadata
{
  "author": "Oskar Austegard and Claude",
  "version": "2.3.0"
}
Other metadata
compatibility
Designed for Claude Code / Claude Code on the Web — assumes an orchestrator with Agent/Workflow subagent tools. Only the Workflow tool sets a subagent's effort; the Agent tool sets its model. Not applicable to claude.ai chat use.

README badge

README badge for oaustegard/claude-skills/agent-routing