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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds behavioral context beyond these: it explains that the config method is 'permanent, non-expiring' while the session method is 'session-only', and describes the flow (call with token or no args to get link). This complements the annotations without contradiction, though it doesn't detail side effects like token overwrite—but that's likely covered by idempotency.

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 front-loaded with the core purpose, then elaborates in two sentences. Every sentence adds value: purpose, permanent method, session method, and no-arg behavior. No filler or redundancy. It's appropriately sized for the tool's simplicity.

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 single-parameter tool with no output schema, the description is complete. It explains both authentication flows, where to get the token, how to pass it, and the consequence of each method. Combined with the annotations, an agent has all needed context to invoke the tool correctly and understand its effects.

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 coverage is 0%, so the description must compensate. It does: it explains the token parameter as a JWT ('{ token: "<jwt>" }') and clarifies that omitting arguments produces a link. This provides meaningful semantic meaning beyond the bare schema, though it doesn't specify token format details beyond JWT or validation constraints.

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: logging in via browser and obtaining an access token for authentication. It specifies the verb (log in) and resource (access token), and distinguishes between two usage methods (permanent config vs session token). No sibling tool serves the same function, so differentiation is implicit but sufficient.

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 guidance: 'Best: add it to this server's config as a header...' for permanent connections, and 'paste it here for a session-only login' as an alternative. It also explains when to call with no args to get the link. This gives clear context on when to use each approach, covering alternatives effectively.

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