login

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

With no annotations, the description carries the full burden and does disclose two non-obvious traits: credentials are persisted for future sessions, and the agent will see the plaintext password (with an instruction to warn the user first). It omits failure behavior and where/how the credential is stored, which keeps it short of full disclosure.

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 clauses, front-loaded with the action, then the persistence note, then the alternative-auth routing. Every sentence carries distinct information with no padding.

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 two-required-param auth tool with no annotations and no output schema, the definition covers purpose, side effect (session persistence), the preferred sibling, and the user-consent step. What's missing is post-login behavior and error/expiry handling, which an agent would otherwise have to discover by calling it.

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, but it only restates the two property names (email, password) with no format, validation, or handling notes. The parameter names are largely self-documenting, so this is adequate but adds little beyond the schema.

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 states a specific verb and resource ("Log in with email + password") and immediately scopes it against the sibling alternative ("Prefer `use_token`"). An agent can distinguish this from `use_token` or `session_info` without opening any schema.

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?

It explicitly names the preferred alternative (`use_token`), which is real routing guidance. It doesn't state when email/password login is actually required (e.g. no token available, first-time setup), so the condition that selects this tool is implied rather than spelled out.

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