login_account

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

With no annotations, the description carries the full burden and does well: it discloses that a browser window is opened, that the session is persisted, and that sign-in and 2FA are manual human steps. It omits blocking/timeout behavior and what happens if a session already exists, but the critical interactive nature is clearly communicated.

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?

Three short sentences, each earning its place: the action, the persistence effect, and the manual step. The key information is front-loaded with no filler.

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?

No output schema exists, and the description covers the essential behavior for a two-parameter authentication tool, including the manual intervention requirement. It could say more about session lifetime or prerequisites for re-login, but nothing critical for calling it correctly is missing.

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 description coverage is 100%, so account_name and region are already fully documented in the schema with examples and the supported region list. The description adds no parameter-level meaning beyond the schema, making the baseline of 3 appropriate.

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?

States a specific verb and resource: opens a browser window to log into an Amazon account. It is unmistakably distinct from siblings like list_accounts, sync_orders, get_orders, and remove_account, all of which operate on an existing session rather than creating one.

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?

Gives clear context for use: the saved session is needed for future order fetches, and sign-in/2FA must be completed manually. However, it names no explicit alternative and does not state when not to use it (e.g. if a session already exists), so the guidance is contextual rather than exhaustive.

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