Plugin Review Agent Skill

Plugin Review

Validate Base MCP plugin files against the current Plugin Specification. Produces a conformance report with actionable findings.

Works for both authors (self-check before submitting a PR) and reviewers (evaluate an incoming PR).

Workflow

• Fetch the current spec (it changes — never rely on a stale copy):

   curl -s https://raw.githubusercontent.com/base/skills/master/skills/base-mcp/references/plugin-spec.md

Related docs worth reading: references/custom-plugins.md, references/approval-mode.md, references/batch-calls.md, and SKILL.md (the root skill). Existing native plugins under skills/base-mcp/plugins/ are the precedent for conventions.

• Read the plugin file in full. If reviewing a PR:

   gh pr view <n> --repo base/skills --json title,body,number,headRefName,files,additions,deletions
   gh pr diff <n> --repo base/skills
   # raw plugin file (diff may be truncated):
   gh api "repos/base/skills/pulls/<n>/files" --jq '.[] | select(.filename|endswith(".md")) | .raw_url'

• Static conformance evaluation — assess against every dimension in references/evaluation-criteria.md (includes compliance/language checks and high-risk category gates). Write the report using references/report-template.md.

• (Optional) Live API / SDK verification — exercise the documented endpoints/SDK/contracts with read-only calls. See references/live-testing.md. For perps/prediction-market/gambling plugins, also run the geoblock verification (compare frontend vs API access restrictions). Append a ## Live API / SDK Verification section to the report. This routinely overturns doc claims (fabricated/locked endpoints, broken hosts, wrong response shapes).

• Save the report. If reviewing a PR and asked to comment, draft a PR comment from the report using references/comment-guidelines.md and post with: gh pr comment <n> --repo base/skills --body-file <comment-file>.

Multiple PRs

Evaluate PRs in parallel by spinning up one sub-agent per PR (each writes its own report + returns a short verdict summary). Hand each sub-agent: the spec (or its raw URL), the PR number, the evaluation criteria, the report template, and the comment guidelines.

Critical gotchas

These recur and are easy to get wrong — full detail in references/evaluation-criteria.md:

• Smart-account signatures break naive signing. The default Base MCP wallet is a smart contract; sign returns a variable-length ERC-1271/6492 signature (>200 bytes), not a 65-byte EOA sig. Any plugin that splices a signature into a fixed-width calldata slot, or bakes an off-chain EIP-712 signature into calldata (e.g. Permit2 buildCallWithPermit2), is broken for that wallet. Correct pattern: onchain allowance grants.
• irreversible risk is NOT for every onchain write. The spec says "flag when worth emphasizing." Pure swaps use slippage (precedent: Uniswap, Aerodrome carry [slippage], not irreversible). Reserve irreversible for asymmetric/severe cases (perps/liquidation, token launches/rug). Do not demand it on swaps.
• Don't self-register. A plugin PR must NOT edit the SKILL.md plugins table, the Integration Types "Examples" cell, or the "Existing Plugin Conformance" table — those are maintainer-managed (codified in plugin-spec.md "Contribution Scope"). The only sanctioned shared-file edit is appending a genuinely net-new tag to the vocabulary list. Limit the diff to plugins/<slug>.md (+ that tag line).
• version is the plugin-doc version — not the npm/package version and not a global spec version. The spec mandates no specific starting number.
• Verify claims, don't trust them. Auth models, allowlist completeness, response shapes, and contract addresses are frequently wrong in the doc. Probe them (live testing).
• Reference links from a plugin file must use ../references/... (plugin files live in plugins/, refs in references/).
• Neutral language is mandatory. No yield/rate/performance claims, no "you should buy X", no "always deposit here", no defaulting to specific tokens. Steering language is a blocker.
• Perps, prediction markets, and privacy plugins need legal review before inclusion as native plugins. Flag this as a pre-merge process gate in the report.
• API geoblock parity. If the protocol's frontend geoblocks US IPs (or others), the API must enforce equivalent restrictions. If it doesn't, Base MCP risks being a circumvention tool — flag as a blocker.