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

Annotations only give the generic profile (readOnlyHint=false, openWorldHint=false, destructiveHint=false). The description adds a real behavioral fact beyond that: 'alle offenen Bildschirme des Stapels folgen', i.e. navigation is stack-wide and changes view state for the whole stack. It does not say what happens if the target board is not in the stack or what is returned, so not a full 5.

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?

A single front-loaded sentence with a parenthetical that earns its place by stating the stack-following side effect. No filler, no redundancy with the title.

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 3-parameter, zero-required navigation tool with no output schema, the description covers both modes and the key state effect. What remains missing is error/invalid-target behavior and any hint of the response, which keeps it from a 5.

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 low (33%): board_id has no description and direction only shows enum [1,-1]. The description compensates well for direction ('1/-1 zum nächsten/vorherigen Bildschirm') and ties stack_id to direction, but leaves board_id's relationship to stack_id ambiguous (must it already belong to that stack? is it mutually exclusive with direction?). This is partial compensation, hence 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 uses a specific verb+resource ('Wechselt ... zum angegebenen Bildschirm') and additionally defines the directional navigation variant, which clearly separates it from CDUD siblings like get_board, clear_board or update_board. It stops short of naming any sibling explicitly, so it earns a 4 rather than 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?

It distinguishes two calling modes (explicit board_id vs. 'direction 1/-1' within a stack), which implies when each parameter set applies. However, it never names alternatives or states exclusions, e.g. what to use instead when you want to read board content (get_board), so guidance is implied rather than explicit.

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