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

Annotations already declare idempotentHint=true and readOnlyHint=false. The description enriches this by disclosing critical behavior: it initiates a browser login, requires copying a token, and differentiates between persistent (config-based) and session-only login, including that the token is a JWT. It also implies that calling without args returns a login link. This goes well beyond the annotations, providing essential side-effect transparency without contradicting any hints.

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 appropriately sized for the complexity, but it's structured as one long run-on sentence that could be parsed more easily. It front-loads the purpose and then explains the two usage modes. Every sentence adds value, but breaking it into bullet points or shorter sentences would improve readability. Still, it is efficient and not bloated.

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 tool with one optional parameter and no output schema, the description is remarkably complete. It covers the authentication flow (browser login, token capture), the two usage modes (permanent via config, session via pasted token), and the no-args behavior. It also cryptically implies the output (a link) without needing an output schema. Given the simplicity of the tool, this is exactly the right level of detail—nothing missing and nothing extraneous.

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?

Though the schema has 0% description coverage, the description fully compensates. It explains the 'token' parameter expects a JWT pasted by the user, and clarifies the semantics of omitting it (returns a link). It also introduces the syntax `{ token: '<jwt>' }` to show input format. This adds substantial meaning beyond the bare schema, turning a cryptic optional string into a well-understood interaction.

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 uses a specific verb ('authenticate') and resource ('MCP.AI for IDE agents'), clearly distinguishing it from siblings like 'connect' or 'marketplace'. It leaves no doubt about what this tool does: establishes authentication for IDE agents via browser login and token handling. The mention of Cursor and IDE agents adds precise context that differentiates it from other tools in the set.

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?

The description explicitly explains when to use this tool (for IDE agents like Cursor), and provides two clear usage paths: a best practice (add to server config for permanent connection) and an alternative (session-only login). It also specifies that calling with no args returns a link. While it doesn't name sibling tools, it gives explicit contextual guidance on both when and how to use it, exceeding the bar for this dimension.

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