List Blocks

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

No annotations are provided, so the description carries the full burden. It states what it lists but doesn't disclose behavioral details like whether it returns aggregated counts across the whole drawing, whether it scans modelspace only (it does say 'in modelspace', which is a useful scoping detail), or what happens if the file_path is invalid. The output schema exists, which helps, but the description adds limited behavioral context beyond the basic call.

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 concise sentence that front-loads the primary action and result. No wasted words, though it could add a hint about file_path format without bloating.

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?

Given the tool has a single required parameter and a provided output schema, the description covers the core purpose. It lacks details like file format expectations and edge-case behavior, but for a simple list operation with output schema available, it's fairly complete. The absence of annotations and explicit usage alternatives slightly lowers this from a 5.

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. The description clarifies that file_path refers to a drawing file containing modelspace, but it doesn't specify the format, whether it's a DXF/DWG, or what the expected file extension is. With only one parameter and no enum, a brief format hint would be helpful but isn't present.

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 verb 'List' and the resource 'block definitions', plus the specific output (usage/instance count) in modelspace. It distinguishes from siblings like list_layers and query_drawing_entities by focusing on block definitions and instance counts, though it doesn't explicitly name a sibling.

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 implies usage: call this tool to get block definitions and their instance counts. It doesn't explicitly state when to prefer this over siblings like query_drawing_entities, but the scope (blocks vs entities vs layers) is reasonably clear. No exclusions or alternatives are mentioned, so it's implied rather than explicit.

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