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

Annotations only declare readOnlyHint=false, so the mutation nature is already known; the description usefully adds the positional precondition (you must already be on the cell). It says nothing about what entering triggers (a dialog, a menu, a state change), what failure looks like, or whether the action is reversible.

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?

One sentence with no filler, and the action is front-loaded before the precondition and the parameter source. The referential phrasing ('по его Z') is slightly compressed but still parseable for an agent familiar with game_look.

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 single-parameter action tool with no output schema and minimal annotations, the definition covers the action, the precondition, and the parameter source. It leaves the agent guessing about the post-entry state and error conditions, which matters for an irreversible-feeling game action.

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 0% and the schema only says 'integer, minimum 1', so the description carries the burden — and it does, by telling the agent where the value comes from ('its Z from game_look'). That is meaningfully more than the schema provides, though it does not clarify the coordinate's origin or valid range beyond minimum 1.

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?

Specific verb + object: 'enter the building' on your current cell. It also implicitly contrasts with game_leave_building by naming the entry action rather than the exit, so an agent can distinguish intent. It stops short of explicitly naming a sibling as the alternative.

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?

The description supplies a real precondition — you must be standing on the cell ('на своей клетке') — which is genuine when-to-use context not available from the schema. It does not state what to do if no building is present, nor does it point to a fallback tool such as game_look or game_move when the precondition fails.

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