Open exercise

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

With no annotations, the description carries the full burden; it does convey that this is a stateful navigation action ('go to the next/previous exercise ... from the open exercise') and that it returns the exercise content. However, it does not say what state is changed (current position, progress, answers) or whether the operation requires an authenticated/launched session.

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 short sentences, verb and resource front-loaded, with the alternative navigation mode and the return behavior stated compactly. Nothing is wasted.

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 three-optional-parameter tool with fully documented schema and no output schema, the description covers the mechanics adequately. It leaves the overlap with beook_read_exercise unresolved and says nothing about the state left behind after opening, which matters for a UI-driving tool.

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 100%, so ref, course, and direction are already documented in the schema, including the enum and the ambiguity condition for course. The description only adds the provenance of ref (from beook_list_exercises) and the fallback baseline for direction, which is a marginal gain.

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 (open) and resource (exercise) and covers both modes: open by reference or step next/previous. It does not distinguish itself from the sibling beook_read_exercise, which likely also returns exercise content, so an agent cannot fully disambiguate the two from this text alone.

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?

Points to the prerequisite source of references (beook_list_exercises) and explains the two invocation modes, including that direction navigation starts from ref or the currently open exercise. It gives no exclusions or guidance on when to prefer beook_read_exercise instead.

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