Agent skill

Tool Surface Discipline

by jgravelle in jgravelle/jcodemunch-mcp

The small-front-door principle and what counts as a tool-surface change.

Custom licenceAuto-check passedAgent Workflows

Install Tool Surface Discipline

skills CLI
$ npx skills add jgravelle/jcodemunch-mcp --skill tool-surface-discipline -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install jgravelle/jcodemunch-mcp tool-surface-discipline --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/jgravelle/jcodemunch-mcp.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/tool-surface-discipline .claude/skills/tool-surface-discipline && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
tool-surface-discipline
GitHub stars
2.8k
Token cost
~389 tokens
SKILL.md length
163 words
Files
1
Skills in repo
10
Repo updated
First seen
Licence
Custom licence

At a glance

The small-front-door principle and what counts as a tool-surface change.

  • Tasks that involve MCP servers
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Tool Surface Discipline is an agent skill from jgravelle/jcodemunch-mcp. The small-front-door principle and what counts as a tool-surface change. Load in /feature step 3, in review, and before editing any tool name, argument, description or tier.

Its SKILL.md is about 390 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Agent Workflows, covering MCP servers. It works with Model Context Protocol. The repository describes itself as: Cut AI token costs 95%+ on code exploration. The leading MCP server for precise, symbol-level GitHub code retrieval via tree-sitter AST. Works with Claude Code, Cursor & any MCP…

When your agent uses it

  • Tasks that involve MCP servers

Example prompts

  • “/tool-surface-discipline”

What it can do on your machine

Read from SKILL.md and the folder at commit 970c457. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Tool Surface Discipline loads about 389 tokens when it runs. Until then it costs about 49 tokens; SKILL.md has 163 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~49
When it runs · the whole SKILL.md, loaded when a task matches
~389

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 163 words (~389 tokens).

“Authority: docs/standard/STANDARD.md criterion 4; CLAUDE.md "Tool-description quality", "Codex tool-surface benchmark", "Tier-switch pricing"; tests/test_schema_budget.py, tests/test_counter_surface_stability.py, tests/test_description_smells.py; scripts/surface_diff.py.”

— opening of SKILL.md by jgravelle, Custom licence
name
tool-surface-discipline

Read the full SKILL.md on GitHub

Files

Just SKILL.md in .claude/skills/tool-surface-discipline of jgravelle/jcodemunch-mcp.

Open the folder on GitHubat commit 970c457

Compare with similar skills

Tool Surface Discipline next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Tool Surface Discipline compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Tool Surface Discipline this skilljgravelle/jcodemunch-mcp2.8k—~389Automated safety check: PassCustom licence
MCP Server Builderanthropics/skills180k63 repos~2.3kAutomated safety check: PassApache-2.0
MCP Server BuildershareAI-lab/learn-claude-code78k4 repos~1.2kAutomated safety check: PassMIT
MCP Integration for Pluginsanthropics/claude-plugins-official38k11 repos~3.1kAutomated safety check: PassApache-2.0
Crush Configurationcharmbracelet/crush29k—~3.7kAutomated safety check: PassCustom licence
Context Mode Output Sandboxmksglu/context-mode26k—~4.1kAutomated safety check: PassCustom licence

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Categories

Questions about Tool Surface Discipline

What does Tool Surface Discipline do?

The small-front-door principle and what counts as a tool-surface change. Tool Surface Discipline is an agent skill from jgravelle/jcodemunch-mcp. The small-front-door principle and what counts as a tool-surface change.

When should I use Tool Surface Discipline?

Tool Surface Discipline fits situations like: tasks that involve MCP servers.

How do I install Tool Surface Discipline in Claude Code?

Run `npx skills add jgravelle/jcodemunch-mcp --skill tool-surface-discipline -a claude-code`. Or copy the skill folder (.claude/skills/tool-surface-discipline in jgravelle/jcodemunch-mcp) into .claude/skills/tool-surface-discipline in your project. Claude Code loads it when a task matches its description.

How do I install Tool Surface Discipline in Codex?

Run `npx skills add jgravelle/jcodemunch-mcp --skill tool-surface-discipline -a codex`. Or copy the skill folder (.claude/skills/tool-surface-discipline in jgravelle/jcodemunch-mcp) into .agents/skills/tool-surface-discipline in your project. Codex loads it when a task matches its description.

Can I use Tool Surface Discipline in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add jgravelle/jcodemunch-mcp --skill tool-surface-discipline -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/tool-surface-discipline, .gemini/skills/tool-surface-discipline, .github/skills/tool-surface-discipline and .opencode/skills/tool-surface-discipline in your project.

What does Tool Surface Discipline need to run?

SKILL.md names no scripts, command-line tools or credentials: Tool Surface Discipline is instructions for the agent only.

Does Tool Surface Discipline access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Tool Surface Discipline safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Tool Surface Discipline use?

Tool Surface Discipline has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.

How many tokens does Tool Surface Discipline use?

About 389 tokens (SKILL.md is roughly 1.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Tool Surface Discipline?

Skills that share tags, products or a category with Tool Surface Discipline: MCP Server Builder (anthropics/skills, 180k stars), MCP Server Builder (shareAI-lab/learn-claude-code, 78k stars), MCP Integration for Plugins (anthropics/claude-plugins-official, 38k stars) and Crush Configuration (charmbracelet/crush, 29k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Tool Surface Discipline?

jgravelle (a GitHub user) maintains it in jgravelle/jcodemunch-mcp, which has 2,754 GitHub stars. The repository holds 10 skills in this directory. The repository was last updated on October 11, 2026.

Source: jgravelle/jcodemunch-mcp on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.