AI agent tools glossary
Plain-English definitions for the building blocks of AI coding agents — what each thing is, in one paragraph you can act on. Every term links to the curated catalog for it.
MCP server
An MCP (Model Context Protocol) server is a small program that gives an AI coding agent like Claude Code, Codex, or Cursor a new capability — a tool, data source, or action it can call directly. Instead of copy-pasting context, the agent connects to the server and uses its tools live, over a standard protocol.
agent skill
An agent skill is a reusable, installable instruction set — a SKILL.md file plus optional scripts and references — that teaches an AI coding agent how to perform a specific task well. Skills are loaded on demand, so an agent gains procedural know-how (a workflow, a convention, a domain) without bloating its base prompt.
marketplace
A marketplace is a registry an AI coding tool can add so it can install plugins and skills from it in one command. Adding a marketplace points the tool at a curated source; from there you install individual entries by name. It is the distribution layer for skills and plugins.
plugin
A plugin packages commands, sub-agents, or skills for an AI coding tool into a single installable unit, distributed through a marketplace. Where a skill teaches one task, a plugin can bundle several capabilities together and is added with one install command after its marketplace is registered.
workflow
A workflow is a multi-step, repeatable automation that chains an AI agent’s actions toward an outcome — for example scaffold, test, review, and open a PR. Workflows encode a sequence and its decision points, so a recurring engineering process runs consistently instead of being re-prompted each time.
Idea phase
The Idea phase is where a builder turns a hunch into a validated opportunity using AI-coding tools - opportunity and competitor research, demand signals, and the skills, MCP servers and workflows that surface them. Skillselion organizes the complete catalog for this phase and highlights the best tools for each job, before you write a line of code.
Validate phase
The Validate phase is where a small team proves an idea is worth building before building it - scoping, prototyping and spikes, landing-page and waitlist tests, and pricing. Skillselion organizes every AI-coding skill, MCP server and workflow for this phase and highlights the best tool for each de-risking step.
Build phase
The Build phase is where a builder ships the actual product without a team - UI and frontend, backend, data and payments, integrations, agent skills and templates, docs and project management. Skillselion organizes the complete catalog of AI-coding skills, MCP servers, marketplaces and workflows for this phase and highlights the best tool for each layer of the stack.
Ship phase
The Ship phase is where a builder makes a release hold up under real users - testing and QA, code review, security, CI/CD and deploy, and performance. Skillselion organizes every AI-coding skill, MCP server and workflow for this phase and highlights the best tool to catch what one person cannot eyeball alone.
Launch phase
The Launch phase is where a builder gets a shipped product found - distribution and launch channels, SEO for web search, app-store optimization, and AI-search / GEO visibility. Skillselion organizes the complete catalog of AI-coding skills, MCP servers and workflows for this phase and highlights the best tool to earn the first wave of attention.
Grow phase
The Grow phase is where a small team turns early users into retained, paying ones - analytics and insights, lifecycle and retention, content and marketing, and support and community. Skillselion organizes every AI-coding skill, MCP server and workflow for this phase and highlights the best tool to compound traction without a growth team.
Operate phase
The Operate phase is where a builder keeps a live product healthy and cheap to run - error tracking, monitoring and observability, infrastructure and cost, and iteration and experiments. Skillselion organizes the complete catalog of AI-coding skills, MCP servers and workflows for this phase and highlights the best tool to stay on top of production alone.