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

Annotations are absent, so the description carries the full behavioral burden and does not meet it. It doesn't say whether the move consumes credits (the npub param implies billing), whether it can fail, whether it's reversible, or what the world state looks like after. 'Move' implies mutation but nothing about cost or side effects is disclosed.

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 tight sentence with no waste. It is front-loaded, but its brevity comes at the cost of the missing detail noted elsewhere rather than being efficiently complete.

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?

No annotations, undocumented dpop_token, opaque domain vocabulary, and no disclosure of billing or failure behavior. An output schema exists so return values needn't be described, but almost everything an agent needs to invoke this correctly is absent.

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 67%; the description adds nothing about to_cell's validity rules ('neighbouring' appears only in the schema), the required-ish npub billing key, or the undocumented dpop_token. For a tool whose only required param is an ambiguous integer with adjacency semantics, the description should explain the coordinate/adjacency model.

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 ('move one cell') and a constrained context ('open air or an open tunnel'), which is more than a tautology. But 'cell' and 'tunnel' are domain jargon that isn't grounded for an external agent, and nothing distinguishes it from siblings like dig or tick.

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?

No when-to-use guidance, no prerequisites, no alternatives. The phrase 'open air or an open tunnel' hints at a precondition but never states what makes a cell open or what happens if it isn't.

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