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

Beyond the readOnlyHint annotation, the description adds meaningful behavioral context: the tool performs no credential handling, never sees passwords, uses a browser-based OAuth flow, and works with no account at all. These details prevent dangerous or confusing invocation attempts and are not present in the structured annotations.

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 description is front-loaded with the core message and then provides necessary explanatory context about why a login/registration tool is absent. It is longer than minimal, but every sentence earns its place by preventing misinterpretation and clarifying the authentication model.

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?

For a zero-parameter, read-only informational tool, the description is fully complete: it states what the tool does, when to use it, why it exists, what it does not do, and how the underlying authentication works. An agent has everything needed to invoke it correctly.

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?

The input schema has zero parameters, which is already complete. The description reinforces that the tool requires no account and takes no arguments, adding no conflicting information. With no parameters to document, this is the appropriate baseline score.

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 clear purpose: it explains how to connect an account to this MCP server. It explicitly distinguishes itself from a login/registration tool by stating that no such MCP tool exists, making its role unmistakable even among many sibling tools.

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 direct usage guidance: read this instead of guessing at a login/registration tool, because there isn't one. It also explains the authentication model (OAuth 2.1 browser flow) and clarifies that the tool works without any prior account, so an agent knows exactly when to invoke it.

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