jamesmoss/agent-school
Investigates a problem area in the codebase and finds or creates a tessl tile (rules, docs, skills) to teach agents how to handle it correctly. Use when agents keep making the same mistakes around a library, design pattern, or convention.
73
73%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Advisory
Suggest reviewing before use
Security
2 findings — 2 medium severity. This skill can be installed but you should review these findings before use.
W011: Third-party content exposure detected (indirect prompt injection risk)
What this means
The skill exposes the agent to untrusted, user-generated content from public third-party sources, creating a risk of indirect prompt injection. This includes browsing arbitrary URLs, reading social media posts or forum comments, and analyzing content from unknown websites.
Why it was flagged
Third-party content exposure detected (high risk: 0.80). The SKILL.md workflow (Phase 2) explicitly instructs the agent to run `tessl search` against the public Tessl registry and to evaluate/install tiles from that registry, meaning the agent will fetch and interpret third-party (potentially untrusted) tile content that can change tool use and steer future agent behavior.
W012: Unverifiable external dependency detected (runtime URL that controls agent)
What this means
The skill fetches instructions or code from an external URL at runtime, and the fetched content directly controls the agent’s prompts or executes code. This dynamic dependency allows the external source to modify the agent’s behavior without any changes to the skill itself.
Why it was flagged
Potentially malicious external URL detected (high risk: 0.80). The SKILL instructs the operator to run "tessl install tessleng/tile-creator" (and similar `tessl install` calls like `tessl install jamesmoss/agent-school`), which fetches remote tile code from the registry at runtime that will be loaded as steering rules/skills and therefore can directly control agent prompts/instructions.
- Audited
- Security analysis