login_with_credentials

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

With no annotations, the description discloses limitations (no 2FA, email confirmation, anti-bot handling), fragility, and DOM interaction. Could mention failure states, but return value description suffices.

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?

Four sentences with no waste: purpose, method, limitations, alternative, return. Front-loaded with key info.

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 zero-parameter tool with an output schema, the description covers behavior, limitations, alternatives, and return value. No gaps.

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?

No parameters exist; schema coverage is 100%. Baseline 4 applies as description adds no unnecessary param context.

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 attempts an automated DOM login using credentials, specifies it is fragile, and distinguishes from the preferred 'login' tool or session cookies.

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?

Explicitly states when to use (only for simple accounts without 2FA/anti-bot challenges) and recommends alternatives: 'Prefer ``login`` or session cookies.'

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