Agent Skills vs MCP vs Prompts: Which Should You Use?
Use a prompt for today's task, a Skill for a repeatable method, project instructions for shared conventions and MCP for a tool or data connection.
Fastest way
Ask your AI to do it
Paste this into the AI agent you already use:
Help me choose between a prompt, project instructions, an Agent Skill and an MCP connection. Ask what repeats, which output I need and whether external data or actions are involved. Explain the smallest setup that fits and the permissions it needs. Do not connect accounts or purchase services on my behalf.
What is the practical difference?
A prompt supplies the current request. A Skill carries a reusable procedure and supporting files. Project instructions describe conventions for a repository. MCP connects an agent to exposed tools or data. One task can use all four; installing one does not automatically provide the others.
Compare the job each layer does
| Layer | Use it for | Example | What it does not supply |
|---|---|---|---|
| Prompt | The facts and goal for one request | Make a proposal from this approved brief. | A maintained package or new tool access |
| Project instructions | Conventions across project tasks | Use our terminology and existing checks. | An external account connection |
| Agent Skill | A repeatable method with optional scripts and assets | Build and review a report using a documented sequence. | Provider credentials or guaranteed correctness |
| MCP connection | Tools and data exposed by a connected server | Retrieve approved records from a connected source. | The complete reasoning and review procedure |
When is a prompt enough?
Start with a prompt when the task is short and the inputs are already available. Specify the output and acceptance criteria. If you repeatedly supply the same examples, calculations or checks, package that reusable method as a Skill. Continue to give today's facts in the prompt.
Inspect what belongs in a skill package
How can a Skill and MCP work together?
For a recurring client report, an approved MCP connection could retrieve records, a reporting Skill could define calculations and presentation steps, and the prompt could specify the period and audience. A supplied CSV may also be enough for a local report. Use a connection only when the task needs its tools or data.
- Agree which data may be read and which actions may be performed.
- Reconcile the final report with its source, regardless of how the data was obtained.
- Verify your own inputs and exports; a sample is not proof of your result.
Check host behavior before combining tools
Does a Skill purchase include MCP or model access?
Skillrove package access and external services are separate. Read the active skill page for files, runtime requirements and provider needs. Model subscriptions, API usage, hosting and connected services can have their own costs. An agent label or package purchase does not connect a new account.
What Skillrove access includes
Choose the smallest useful setup
- For one draft, start with a prompt and approved facts.
- For a recurring method, compare a Skill's real example and documented files.
- For project conventions, use the instruction mechanism your agent supports.
- For external tools or data, assess the connection and its permissions.