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

Beyond the annotations (idempotent, non-destructive), the description adds valuable behavioral detail: calling with no args returns a link, and calling with a token triggers a session-only login. This clearly explains what the tool does in each mode, with no contradiction to 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 concise with three sentences, front-loading the purpose. The middle recommendation about server config is slightly tangential but still earns its place as guidance, so it's well-structured and not wasteful.

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 simple one-parameter auth tool, the description adequately covers the two main usage modes. It does not specify the return value format, but that is not critical for this tool and not required by the schema.

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?

Since schema coverage is 0%, the description fully compensates by explaining the token parameter as a JWT for session login and clarifying that it is optional (no args yields a link). This is excellent semantic enrichment beyond the bare schema.

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 is for authenticating with MCP.AI for IDE agents, explaining the process of logging in and copying an access token. It does not explicitly differentiate from sibling tools like 'connect', so it misses the top score for sibling distinction.

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 gives explicit usage scenarios: a recommended permanent config via header, and a session-only login via token or no-args to get a link. It provides clear context but no mention of alternative tools or when not to use this tool, so it lacks the 'when-not' component.

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