bb_login

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

With no annotations at all, the description carries the full burden and does a good job: it discloses that a Chrome window opens, that a human must complete SSO + MFA, and that a silent refresh is attempted first so it often completes headlessly. It still omits failure/timeout behavior and what state is persisted on success.

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, front-loaded with the core action, then the interaction model, then the silent-refresh nuance. Every clause earns its place and there is no filler.

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 an auth tool with no output schema and a thin input schema, the description supplies the essential mental model an agent needs (human-in-the-loop, browser window, silent refresh). The remaining gap is the undocumented timeout parameter and the absence of any statement about what a successful or timed-out result looks like.

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?

There is one parameter (timeout_seconds) with 0% schema description coverage, and the description never mentions it or explains what it bounds (presumably how long to wait for the student to finish SSO/MFA). The description therefore adds no meaning beyond the bare default in 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?

States a specific verb and resource ('Sign in to Blackboard'), which is unambiguous and clearly distinct in kind from the data-retrieval siblings (bb_courses, bb_browse, bb_download). It does not explicitly name a sibling or say where it sits in the workflow relative to them, so it falls just short of a 5.

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?

Usage is implied rather than stated: an agent can infer this is the prerequisite auth step, and the note that it tries a silent refresh first hints it is safe to call even when a session may already exist. There is no explicit when-to-use, when-not-to-use, or ordering guidance versus bb_status or the other bb_* tools.

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