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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose the scanning order ('from the top-left') and that the operation is 'Free,' which adds useful behavior beyond the title. However, it does not mention response shape, pagination, rate limits, or any side effects.

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?

The description is extremely concise: a short noun phrase plus one clarifying word. It front-loads the core purpose and avoids redundant phrasing or filler, making every word useful.

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 simple tool with no annotations and no output schema, this is a reasonable but minimal description. It states the result type, ordering, and cost, but it omits any guidance about when to use the tool and does not clarify whether the default limit behavior needs attention.

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?

The input schema fully documents the single 'limit' parameter, including its range and default, so the description does not need to repeat that information. The description adds no extra parameter meaning, but the high schema coverage justifies the baseline score of 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 clearly identifies the resource ('unclaimed blocks') and the result ('Coordinates'), and the title adds 'Find unclaimed blocks.' This is enough to distinguish it from siblings like buy_block or set_pixels, though it lacks an explicit verb in the description itself.

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 guidance is given about when to use this tool versus alternatives such as get_block, buy_block, or set_pixels. The 'Free' note hints at cost, but the description does not say when this tool is appropriate or when another tool should be chosen.

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