Log in to Scratch

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

With no annotations, the description carries the full burden. It discloses that the session is kept in memory only for this server process, that credentials default to environment variables, and that saving/publishing require confirmation. It doesn't mention potential rate limits or security nuances, but for a login tool this is a solid level of transparency.

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?

Two sentences with zero fluff. The core purpose and effect are front-loaded, followed by the env-var fallback and session lifetime. Every part earns its place.

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 login tool with two optional parameters fully covered by the schema, the description is complete. It explains the consequences (session in memory) and the confirmation behavior. One minor gap: it doesn't explicitly state that login must occur before other tool calls, but that is strongly implied by the purpose statement.

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 input schema already fully describes both parameters, including their env-var defaults. The description restates the defaults but adds no new syntax or meaning beyond the schema. Per the rubric, with 100% schema coverage this is a baseline 3.

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 action (authenticate) and the target resource (scratch.mit.edu account), and explains why it matters (open projects, save edits, publish). It distinguishes itself from the many project/sprites tools by focusing solely on authentication, so an agent can easily tell this is the login step.

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 implies that login is a prerequisite for other server operations (opening projects, saving, publishing) and explains the confirmation flow for writes. It doesn't explicitly say 'use before other tools' or list alternatives, but given the sibling list has no other auth tool, this is clear enough. The env-var default is a handy usage note.

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