x_login

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

Annotations only set readOnlyHint=false. The description adds significant behavioral context: it performs login, may challenge with email or TOTP, enables session-level access, and discloses security implications of passing password through AI context. This goes well beyond annotation hints.

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 concise with two short paragraphs. The first paragraph front-loads the core action and usage, the second adds a crucial security note. Every sentence adds value, though minor redundancy exists (e.g., 'SECURITY:' label could be integrated).

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 is provided. The description does not mention the return value or what indicates success/failure, which is a gap for an authentication tool. However, given the tool's simplicity and the thoroughness on other dimensions, it is adequate but not fully complete.

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 covers 100% of parameters with descriptions. The description adds practical usage context: email is 'Required-in-practice' due to conditional verification, and totp_secret is needed for 2FA. This supplements schema info without redundancy.

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 purpose: logging into an X account to enable write/private tools. It uses specific verb 'Log into' and resource 'X account', and distinguishes from sibling tools which are all account actions that require prior authentication.

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 (to enable write/private tools) and provides an alternative (set X_AUTH_TOKEN in config to skip this tool). Also includes security warning for sensitive accounts, guiding the agent on when not to use it.

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