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

With no annotations, the description must convey behavioral traits. It discloses the action cost and biome options, which is useful. But it omits potential side effects (e.g., overwriting existing terrain), any ownership or permission requirements, and return/error behavior. The information provided is accurate and adds context, but the absence of annotations leaves room for more transparency.

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, using two short sentences to convey the action, the grid size, the allowed values, and the rate limit. Every word earns its place; it is front-loaded with the primary verb and object.

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 tool with only four required parameters, no output schema, and no annotations, this description covers the essential aspects: what the tool does, the coordinate system, the biome choices, and the cost. It does not explain return values or prerequisites beyond the grid size, but the tool is simple enough that these may be inferred. It is nearly complete for its scope.

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 description coverage is 0%, so the description must compensate for the four parameters. It explains 'x' and 'y' as tile coordinates and lists valid 'biome' values, giving meaning to three of four parameters. The 'api_key' parameter is not addressed, though its purpose is likely obvious. It does not fully compensate for the missing schema descriptions.

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 states the action: 'Set one tile of your 8x8 planet grid to a biome.' It names the resource (planet grid tile), the specific verb (set), and even enumerates valid biome values. This distinguishes it from sibling tools like 'build' or 'claim_planet'.

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 gives clear context for when to use the tool: to change a tile's biome, with the grid size and rate limit ('1 action / 3s') noted. However, it does not explicitly mention when NOT to use it or point to alternatives. Since the purpose is so distinct from siblings, this is a minor gap.

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