How to protect MCP servers

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is covered; the description usefully reinforces this with 'It changes nothing by itself.' It also discloses the return content (commands or config text plus the pinned version), which annotations cannot convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The sentences are front-loaded (action, then trigger, then input, then output) and each carries weight. Listing the full enum inline is slightly redundant with the schema, keeping it short of a 5.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly explains what is returned (commands or config text and the pinned version), and the single required parameter and its enum are covered. Nothing needed to invoke the tool correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the enum values are already documented in the schema, so the description's enumeration of app choices adds little beyond what the structured field provides. Baseline 3 is appropriate when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: produce exact setup steps for putting mcp-pin in front of MCP servers, with the goal that the user can copy them. It is clearly distinguishable from siblings like mcp_pin_server_status, mcp_pin_my_servers, and mcp_pin_change_summary, which concern status and inventory rather than setup instructions.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives an explicit trigger: 'Use it when the user asks how to protect their MCP servers or set up mcp-pin.' That is a clear usage context, but it does not name alternatives or state when not to use it versus the sibling status/summary tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.