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

Annotations indicate non-readonly, idempotent, non-destructive. The description adds valuable context: browser login steps, token permanence (non-expiring vs session-only), and behavior of no-args invocation (returns link). No contradictions with 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 a single, long sentence but flows logically with structure ('Best:' vs 'Or'). It front-loads the core idea and avoids redundancy, though it could be slightly more concise without losing meaning.

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 simple input schema and lack of output schema, the description covers the essential aspects: auth mechanism, parameter semantics, and two usage modes. It does not detail return values or error handling, but for an auth tool this is acceptable.

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 has only an optional token parameter with no description. The tool description fully compensates: it clarifies that token is a JWT for session-only login, and that calling with no args returns the login link. This entirely clarifies parameter usage and optionality.

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: authenticate to the MCP server via browser login and token exchange. It distinguishes from siblings by describing specific auth flows (permanent config vs session-only), but does not explicitly name alternatives like 'connect'.

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 guidance: call with no args to get a login link, or with a token for session-only login. It also explains the permanent alternative (adding to server config). However, it lacks a direct comparison to sibling tools or exclusions like 'when not to use'.

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