reddit_auth_login

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

Beyond the annotations, the description discloses that it opens the consent page, catches the callback on a loopback port, stores a refresh token, and is a one-time step. This gives an agent an accurate model of the side effects without contradicting idempotentHint or destructiveHint.

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 tight sentences, front-loaded with the core action and followed by the behavioral and use-case context. No filler or repetition of schema content.

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 tool with no required parameters and no output schema, the description fully covers purpose, side effects, prerequisites, and when it is needed. The parameter details are covered by the schema, so nothing important is missing for selection and invocation.

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 single 'open' parameter is already documented with 100% schema coverage, including the headless-machine case and the returned authorize_url. The description only implicitly relates to the default behavior and adds no new parameter-level semantics.

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?

States a specific action ('Sign in to Reddit in a browser') and describes the exact mechanism (consent page, loopback callback, refresh token). It is distinct from sibling auth tools like auth_status, auth_logout, and auth_url.

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 says when login is needed — subscriptions, saved posts, inbox, and any write operation — and says public browsing/search already work without it. It does not name sibling auth alternatives explicitly, but the condition is clear.

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