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

Annotations include idempotentHint=true, readOnlyHint=false, and no destructive hint. The description does not contradict these, but it adds context about the login flow (browser, token, session vs permanent) which is beyond the annotations. However, it doesn't explicitly state whether the tool has side effects beyond setting authentication state, but the annotations already hint that it's not read-only and is idempotent. Given the annotations, the description adds some value but not rich behavioral detail, so a 3 is appropriate.

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 a single paragraph but well-structured, front-loaded with purpose and user audience, then clear instructions. It is concise, every sentence serves a purpose, and it avoids fluff. It might be a bit dense but is appropriately sized for the complexity of authentication flows.

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?

The tool has 1 optional parameter, no output schema, and moderate complexity for authentication. The description covers the token parameter and the two call modes, which is sufficient. It doesn't elaborate on return values, but with no output schema, the description doesn't need to. It provides enough context for an agent to use the tool correctly, though additional details on what the response looks like could improve completeness. Score 4.

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 has 1 optional token parameter with 0% coverage, meaning no description in schema. The tool description clarifies that 'token' is the JWT to paste for session login, and that calling without args generates a link. This adds essential meaning beyond the schema, making the parameter semantics clear. The description effectively compensates for the low schema coverage, so score 4.

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: to authenticate MCP.AI for IDE agents, with a login flow involving a browser and token. It specifies the main use case and distinguishes it from siblings like 'connect' by focusing on authentication and token handling. However, it could be more explicit that this tool is the primary entry point for authentication, but it's clear enough.

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 provides usage scenarios: recommending adding the token to the server's config for a permanent connection, or pasting it here for session-only login. It also clarifies two invocation modes: with token argument after user pastes, or with no args to get the link. This is strong guidance on when and how to use the tool, including alternatives (config vs paste), meeting the 'when/when-not/alternatives' criterion.

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