account_login

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

Annotations provide only a title, so the description carries the full burden of behavioral disclosure. It thoroughly explains that the tool creates a session, never fills credentials or solves challenges, writes cookies back after every action, and reports statuses ('logged_in', 'waiting', 'opened'). It also discloses the handoff mechanism and verify spec stamping. No contradictions with annotations exist.

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 long but densely packed with necessary information. It front-loads the core purpose, then covers predicate behavior, cookie persistence, and status outcomes. While it could be better structured with bullet points, every sentence adds value and avoids fluff. It is appropriately sized for the tool's complexity.

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 tool's complexity, the description covers the essential behaviors: login gate detection, session handoff, verify spec stamping, and status values. It mentions the session_verdict classification and the /live handoff but does not detail every edge case, such as error handling or exact return structure. Still, it provides enough for an agent to call the tool correctly in most scenarios.

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 100%, so the baseline is 3. The description adds meaningful context beyond the schema: it explains how 'predicate' drives the automatic-login wait and stamps the verify spec, how 'use_proxy' seeds a fresh account, and how 'timeout_ms' is never spent during human steps. These details help an agent choose and configure parameters correctly, exceeding the baseline.

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 opens with a specific verb and resource: 'Open a site's login page AS a named account and close the login loop.' It clearly states the tool's primary function and distinguishes it from siblings like account_verify (which re-checks a verify spec) and session_* tools. The purpose is unambiguous and actionable.

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 provides clear context for when to use the tool, including the predicate parameter for waiting on automatic login bounce, and how to handle human gates by using session_wait/session_input or re-calling account_login. It references account_verify as a follow-up step, but does not explicitly state when to prefer alternatives like session_navigate or session_create. This is strong guidance but not fully explicit about exclusions.

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