ext-skills/docs/related-work.md
hcjmartin f1f66fa7f8
docs: add integrity and verification related work (#123)
* docs: add skill-set to related work

Adds skill-set under Specifications and Standards as related work for deterministic whole-skill and set-level hashing, receipt-time verification, and out-of-band content pins.

* docs: add integrity and verification section

Move skill-set from Specifications and Standards into a new   resource integrity and verification section.
2026-08-17 09:36:52 -07:00

11 KiB

Related Work

SEPs and Proposals

Proposal Venue Description
SEP-2640 (Skills Extension) MCP Spec This WG's proposed extension: skills served over MCP using the Resources primitive and skill:// URI scheme (v1 baseline text)
PR #2527 MCP Spec Recommend clients expose resource read to models — prerequisite for the resources-based skills approach
skills.json format proposal MCP Registry Skills metadata in registry schema
SEP-2093 MCP Spec Resource Contents Metadata and Capabilities: scoped resources/list, per-resource capabilities, resources/metadata endpoint — rejected (labeled upstream)
SEP-2076 MCP Spec Agent Skills as a first-class MCP primitive — closed (2026-02-24, without merge)

Working Group Member Implementations

Work by WG leads and active participants that directly implements the group's core patterns: SKILL.md with YAML frontmatter, skill:// resource URIs, and progressive disclosure via MCP primitives.

Implementation Author URL Notes
skilljack-mcp Ola Hungerford github.com/olaservo/skilljack-mcp SKILL.md, skill:// resources, tools, and prompts; progressive disclosure (index→skill→files); file watching for dynamic updates; audience annotations
skills-over-mcp Keith Groves github.com/keithagroves/skills-over-mcp SKILL.md, skill:// resources with progressive disclosure (index→skill→documents); Zod validation against Agent Skills spec
skillsdotnet Peder HP github.com/PederHP/skillsdotnet C# implementation: SKILL.md, skill:// resources, load_skill tool for progressive disclosure, manifest with file hashes; published on NuGet; compatible with FastMCP 3.0

Alternative Approaches

Work by WG members and MCP maintainers that explores skills over MCP through different technical approaches than the core SKILL.md / skill:// pattern.

Implementation Author Organization URL Notes
skillful-mcp Kurtis Van Gent Google Cloud github.com/kurtisvg/skillful-mcp Progressive disclosure via 4 lightweight tools (list_skills, use_skill, read_resource, execute_code); wraps downstream MCP servers as skills using mcp.json config rather than SKILL.md; sandboxed code execution via Monty
Astronomer agents Kaxil Naik Astronomer github.com/astronomer/agents Production skills catalog for Apache Airflow (blueprint, migration, warehouse-init); uses SKILL.md frontmatter but distributed via plugin marketplace rather than MCP resources; demonstrates real-world skills adoption at scale
mcpGraph skill Bob Dickinson TeamSpark.ai github.com/TeamSparkAI/mcpGraph Declarative YAML-based tool orchestration engine (directed graphs of MCP tool calls); includes SKILL.md files as documentation; explores a complementary "no-code composition" approach to skill authoring

Other Community Implementations

External projects building on skills patterns or integrating skills into frameworks.

Implementation Author URL Notes
FastMCP 3.0 Skills FastMCP gofastmcp.com/servers/providers/skills Native skills provider (#2694)
PydanticAI Skills PydanticAI pydantic/pydantic-ai#3780 Agent skills with tools-based approach
mcp-execution bug-ops github.com/bug-ops/mcp-execution Compiles MCP servers into skill packages; --dry-run preview
mcp-cli philschmid github.com/philschmid/mcp-cli Wraps MCP servers as CLI for progressive disclosure
my-cool-proxy karashiiro github.com/karashiiro/my-cool-proxy MCP gateway with skills as resources via Lua scripts; result offloading, session persistence (v1.6.x)
NimbleBrain skills repo NimbleBrain github.com/NimbleBrainInc/skills Monorepo with .skill artifact format
NimbleBrain registry NimbleBrain registry.nimbletools.ai Registry with skill metadata support
NimbleBrain skill:// servers NimbleBrain github.com/NimbleBrainInc skill:// resource colocation examples: mcp-ipinfo, mcp-webfetch, mcp-pdfco, mcp-folk, mcp-brave-search
Kiro powers directory Kiro github.com/kirodotdev/powers Plugin directory bundling skills + MCP servers; active catalog (AWS, GCP migration, SAM, etc.)
mcpkit (ext/skills) Sri Panyam github.com/panyam/mcpkit Go SDK, server + host: SKILL.md, skill:// resources, progressive disclosure (skill://index.json catalog + host load_skill tool); per-supporting-file digests with verified reads, resource-fetch size + per-server byte budget, resources/directory/read; no code-execution surface (enforced by a build-failing test); released in v0.3.0

Projects that illustrate the problem space or use adjacent patterns.

Project Author URL Notes
chrome-devtools-mcp Google (ChromeDevTools) github.com/ChromeDevTools/chrome-devtools-mcp Real-world example of the problem: skills/ folder requires separate install path
Strands Agents MCP server AWS github.com/strands-agents/mcp-server Docs-as-MCP: TF-IDF search + doc fetch
AWS MCP server AWS docs.aws.amazon.com/aws-mcp/… retrieve_agent_sop (skills) + call_aws (tool)

Specifications and Standards

  • Agent Skills Standard: agentskills.io
  • Agent Skills Discovery RFC v0.2.0 (Matt Silverlock / Cloudflare): github.com/cloudflare/agent-skills-discovery-rfc — Domain-level skill discovery using /.well-known/agent-skills/ (RFC 8615). Defines index.json with progressive disclosure, skill-md and archive distribution types, $schema versioning, SHA-256 content integrity, and archive safety requirements. Complementary to MCP-level discovery: .well-known answers "what skills does this domain publish?" while MCP answers "how does the agent consume them at runtime?"
  • Skill dependency declaration: agentskills/agentskills#110 — Discusses how skills should declare their tool/server dependencies
  • Apache Airflow AIP-91 (MCP integration): cwiki.apache.org/…/AIP-91+-+MCP

Integrity, Content Addressing, and Attestation

Related work on establishing and verifying the integrity, authenticity, and provenance of skill resources.

  • skill-set format (draft) (Harry Martin / flocker.md): skill-set.md — Transport-agnostic manifest specification and CLI for named, versioned collections of skills assembled from disparate sources. Defines deterministic whole-skill content hashes and set-level roll-ups, lockfiles, receipt-time content verification, and optional out-of-band URL-fragment pins. Complementary to SEP-2640: provides prior art for deriving a single content address from a complete {uri, digest} resource set and for future whole-skill or multi-skill attestations. See the reference directory for an immutable example.

Background Reading

  • Anthropic's guidance on progressive disclosure: Equipping agents for the real world with agent skills
  • "MCP and Skills: Why Not Both?" (Kurtis Van Gent): kvg.dev/posts/20260125-skills-and-mcp/ — Frames MCP (connectivity) and Skills (context saturation) as complementary; discusses hybrid approaches
  • "Skills Over MCP" (Angie Jones, Agentic AI Foundation): aaif.io/blog/skills-over-mcp/ — "Ship the manual with the product": bundle Agent Skills with MCP servers so agents get both tools and instructional guidance. Describes the working group's proposal (SEP-2640) — skill:// resources, a skill://index.json catalog for lightweight discovery, and progressive disclosure of full instructions on demand
  • "Progressive Discovery in MCP, Part 2" (Sam Morrow, GitHub MCP Server maintainer): sam-morrow.com/blog/progressive-discovery-in-mcp-part-2 — Advocates skills-based progressive discovery to solve tool bloat: skill:// resources, deferred tool loading via provider mechanisms (Anthropic tool_reference, OpenAI defer_loading), and the io.modelcontextprotocol/tools metadata namespace. Grounded in lessons from GitHub's MCP Server (100+ tools, 12M weekly calls)
  • Conceptual spec visualization (Keith Groves): enact-465fb1fc.mintlify.app/specification/draft/server/skills — "What if" exploration
  • llms.txt convention: llmstxt.org — Convention for making documentation LLM-accessible; used by MCPDoc in a way similar to how skills work
  • AWS Agent SOPs: docs.aws.amazon.com/…/agent-sops — Pre-built operational workflows as skill-like guidance
  • Video background: youtube.com/watch?v=CEvIs9y1uog