Discovery Scanner

What Discovery Scanner is

Discovery Scanner is a subagent published in the jeremylongshore/tons-of-skills-marketplace repository on GitHub, which has about 2.8k stars. The repository describes itself as: “Model-agnostic agent-skills platform with a harness-free canonical layer, verified adapters, and the ccpi package manager. Explore at tonsofskills.com.”

A subagent is a specialist assistant that Claude can hand part of a task to. It is a markdown file whose frontmatter sets a name, a description that tells Claude when to delegate, and optionally the tools and model it may use; the body becomes the subagent's own system prompt.

Because a subagent works in its own context, it keeps the main conversation focused: Claude can send a narrow job, such as a review or a specialised analysis, to Discovery Scanner and get back a compact result.

How to install Discovery Scanner

New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.

Inside the source file

An excerpt from plugins/database/freshie-inventory-manager/agents/discovery-scanner.md, shared under the repository's MIT license. Read the full file on GitHub.

sqlite3 freshie/inventory.sqlite "SELECT id, run_date, total_plugins, total_skills, COALESCE(total_packs, 0) as total_packs FROM discovery_runs ORDER BY id DESC LIMIT 1;"

python3 freshie/scripts/rebuild-inventory.py

sqlite3 freshie/inventory.sqlite "
  SELECT
    d1.id as new_run, d1.total_plugins as new_plugins, d1.total_skills as new_skills,
    COALESCE(d1.total_packs, 0) as new_packs,
    d2.id as old_run, d2.total_plugins as old_plugins, d2.total_skills as old_skills,
    COALESCE(d2.total_packs, 0) as old_packs,
    d1.total_plugins - d2.total_plugins as plugin_delta,
    d1.total_skills - d2.total_skills as skill_delta
  FROM discovery_runs d1
  JOIN discovery_runs d2 ON d2.id = d1.id - 1
  ORDER BY d1.id DESC LIMIT 1;
"

DISCOVERY SCAN COMPLETE
========================
New Run:  #{id} ({date})
Previous: #{id} ({date})

Plugins: {old} → {new} ({+/-delta})
Skills:  {old} → {new} ({+/-delta})
Packs:   {old} → {new} ({+/-delta})

Scan duration: {time}

Before you install

• Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
• Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
• Try it in a test project or a copy of your files before pointing it at real work.
• Pin the version you tested, and review changes before updating.
• Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.

FAQ