create_block

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

With no annotations, the description discloses that the selected entities become the block definition and that the block is not placed until insert_block is used. However, it omits important behavioral details such as whether the original entities are deleted, how naming conflicts are handled, and any preconditions for selecting entities.

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 a single, front-loaded sentence that states the main action and resource. The parenthetical efficiently adds a key alternative without wasting words, making it concise and well-structured.

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?

The description covers the core purpose and the relationship to insert_block, but it does not explain the base point, the fate of source entities, or any prerequisites. With 4 required parameters and no annotations, the context is incomplete, though the output schema covers return values.

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. It adds meaning to 'handles' by referring to 'existing entities', but it provides no explanation for the required base_x and base_y parameters. While the parameter names are somewhat self-explanatory, the description does not fully cover all parameters.

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 'Define' with a clear resource 'a reusable block' and specifies the source as 'existing entities'. It also explicitly distinguishes from the sibling insert_block by noting 're-place with insert_block', fully clarifying the tool's purpose.

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 provides explicit guidance by naming insert_block as the tool for re-placement, giving a clear when-not and alternative. This directly helps an agent select between the two tools and implies the appropriate use case for creating a block definition.

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