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

Annotations already indicate idempotent and non-destructive behavior. The description adds meaningful context: non-expiring vs session-only login, the token being a JWT, and that no-args returns the login link. This is sufficient for a simple tool, though it doesn't mention what happens with invalid tokens.

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 two concise sentences with the purpose front-loaded, followed by clear usage alternatives. Every clause adds value; no filler or redundant restatement.

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?

Given the tool has only one optional parameter and no output schema, the description is complete: it covers both input modes, the no-argument case, and the permanent config alternative. An agent has all the information 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 schema only defines `token` as a string with no description, so the description compensates well: it explains that `token` is a JWT for session-only login and that calling without it returns the login link. This adds the semantics the schema lacks.

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 clearly states the tool's purpose: authenticating an MCP.AI server for IDE agents via browser login and token. It distinguishes itself from sibling tools by explaining the two login modes (config header or session token), which is specific and actionable.

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 explicit when-to-use guidance: configure the token in the server config for permanent access, or call with a pasted token for session-only login, or call with no args to get the login link. This fully explains the invocation options and their trade-offs.

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