What You’ll Learn

  • How I decide which MCP tools are worth building first
  • Why most bad MCP servers fail at workflow selection, not implementation
  • A practical scoring system for tool ideas
  • How to design tool boundaries that Claude can use reliably
  • What kinds of tools usually create value fastest in client work

Building an MCP server is not the hard part anymore. Picking the right tool surface is.

That is where a lot of teams waste time.

They hear that Claude Code can call tools, so they start exposing everything: ten endpoints, three database actions, five internal scripts, a pile of resources, maybe a prompt or two. Technically, they built an MCP server. Practically, they created a noisy interface with no clear priority.

The result is predictable. The tools exist, but they are not actually helping much. Claude does not have the right high-signal actions to reach for, and the team still ends up copying data into chat manually.

What matters more than the server itself is choosing the first few tools that improve an actual workflow.

Start with Friction, Not Features

I do not start by asking, “What can our system expose?”

I start by asking, “What are we repeatedly doing by hand that Claude could do with one safe, structured call?”

That question usually leads to better MCP tools immediately.

Examples:

  • reading the status of a deployment
  • summarizing a large log file into a short diagnosis
  • looking up a customer record by email
  • checking whether a feature flag is enabled in a given environment
  • finding recent errors related to a release

Those are good first tools because they remove repetition. They do not exist just to prove that MCP works.

My Rule: Prefer Read-Heavy Tools First

The fastest path to a useful MCP server is usually read operations, not write operations.

Read-heavy tools are easier to trust because they:

  • have lower blast radius
  • are easier to test
  • are easier to explain
  • give Claude better situational awareness before it takes action

That means my first wave of tools usually looks like this:

  • get-deployment-status
  • list-recent-errors
  • find-customer-by-email
  • get-feature-flag
  • get-order-summary

Write tools come later, after the read side proves useful and the workflow is stable.

This is especially important in client work. A safe read tool builds confidence quickly. A badly chosen write tool creates cleanup tickets.

Score Tool Ideas Before You Build Them

I like scoring MCP tool ideas with a simple rubric instead of arguing about them abstractly.

Here is a small TypeScript version of the idea:

type ToolIdea = {
  name: string;
  repetition: number;
  clarity: number;
  safety: number;
  usefulness: number;
};

function scoreTool(tool: ToolIdea) {
  return (
    tool.repetition * 3 +
    tool.usefulness * 3 +
    tool.clarity * 2 +
    tool.safety * 2
  );
}

const ideas: ToolIdea[] = [
  { name: 'get-deployment-status', repetition: 8, clarity: 9, safety: 10, usefulness: 8 },
  { name: 'refund-customer', repetition: 2, clarity: 6, safety: 3, usefulness: 7 },
  { name: 'list-recent-errors', repetition: 7, clarity: 8, safety: 10, usefulness: 9 },
];

console.log(ideas.sort((a, b) => scoreTool(b) - scoreTool(a)));

The exact numbers do not matter. What matters is forcing the discussion into something concrete.

Good early tools usually score well on these four dimensions:

  • repeated often
  • clearly defined inputs and outputs
  • low operational risk
  • immediately useful inside a coding or debugging workflow

Design Tools for Claude, Not for Your Internal Architecture

One common mistake is exposing tools that mirror internal implementation details instead of user-facing tasks.

Bad tool names:

  • fetchEntity
  • runServiceAction
  • queryAdapter

Better tool names:

  • get-user-subscription
  • list-recent-build-failures
  • find-order-by-id
  • get-release-summary

Claude works better with verbs and nouns that map to a real task. So do humans reviewing the server later.

This also helps with descriptions and schemas. A tool should explain itself without requiring internal tribal knowledge.

Here is the kind of registration shape I like:

server.registerTool(
  'get-release-summary',
  {
    description: 'Return the latest deployment status, release id, and top error signals for a service.',
    inputSchema: z.object({
      service: z.string().describe('The internal service name'),
      environment: z.enum(['staging', 'production']),
    }),
  },
  async ({ service, environment }) => {
    return {
      content: [
        {
          type: 'text',
          text: `Release summary for ${service} in ${environment}...`,
        },
      ],
    };
  },
);

The tool name is clear. The input is constrained. The result maps to a question a developer would actually ask.

Avoid the “One Tool Does Everything” Trap

When teams realize they need to keep the tool list small, they often overcorrect and build one giant tool with a mode parameter.

That usually makes things worse.

If a tool handles five unrelated tasks depending on flags, it becomes harder to describe, harder to validate, and harder for Claude to use consistently.

I would rather have:

  • get-order-summary
  • list-order-events
  • get-customer-subscription

than one vague tool like:

  • query-business-object

Small, specific tools are easier to trust and easier to evolve.

The Best Early MCP Tools in Client Projects

Across real projects, I keep seeing the same high-value categories:

Operational lookup tools

These answer “what is going on right now?”

Examples:

  • deployment status
  • feature flags
  • incident summaries
  • recent error groups

Internal data retrieval tools

These answer “what do we know about this customer / record / order?”

Examples:

  • customer lookup
  • order summary
  • invoice status
  • recent account activity

Workflow compression tools

These answer “can Claude do three repetitive steps in one call?”

Examples:

  • summarize logs
  • convert raw issue data into a release brief
  • turn ticket details into an implementation checklist

The common theme is simple: each tool shrinks real workflow friction.

Final Thought

The difference between a useful MCP server and a noisy one is rarely the transport or the SDK. It is tool selection.

If you choose high-signal, low-risk, task-shaped tools first, Claude becomes more useful immediately. If you expose a random slice of your internal platform, you usually just create more context for everyone to sift through.

Build the tools people keep wishing existed in the middle of work. That is the right starting point.

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