willys_login

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

With no annotations, the description fully discloses key behaviors: credentials are read server-side, sessions are cached for 24 hours, and force=true triggers a new login. It also hints at rate limiting via the schema, but the description itself proactively communicates the safety and reuse behavior, which is essential for the agent.

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 two sentences long, front-loaded with the core purpose, and every clause adds useful information. There is no redundancy or filler, making it highly efficient.

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 simple tool with one optional parameter and no output schema, the description covers all necessary aspects: what it does, safety implications, session reuse policy, and the force option. It is sufficiently complete for the agent to invoke the tool correctly and safely.

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?

The schema already covers the force parameter at 100%, so the baseline is 3. The description adds value by explaining the purpose of force=true in the context of session reuse and the rationale for using it sparingly (based on schema's rate-limiting note), enhancing the agent's understanding of when to set it.

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's function: logging in to Willys and returning a sessionId. This distinguishes it from sibling tools like willys_check_auth (checks authentication) and willys_logout (ends session), making the purpose unambiguous.

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 on when to use the tool: it is safe to call because credentials are read from .env and never enter the agent's context. It also explains session reuse and the force parameter for new logins, though it does not explicitly mention alternatives like check_auth or logout.

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