get_blendfile_summary_datablocks_for_cli

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

Annotations already declare readOnlyHint=true, so the read-only nature is known. The description adds the detail 'opening *blend_file* in background Blender', which implies a non-interactive execution context, a useful behavioral trait beyond the annotation. It does not describe any other side effects, but given the annotation coverage, this is acceptable.

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 sentence that immediately states the action and context. It is concise, front-loaded with the core purpose, and contains no filler. Every word contributes to understanding the tool's function.

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 simplicity of the tool (one parameter) and the presence of an output schema, the description is mostly adequate. However, it lacks any mention of prerequisites (e.g., Blender installation) or a note distinguishing this from the non-CLI sibling. While the background Blender detail helps, the description could be more complete by clarifying when to use the CLI variant.

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 only parameter, blend_file, is a string, and the description simply says 'opening *blend_file*' without adding any detail about what constitutes a valid path, format, or any constraints. The parameter name is somewhat self-explanatory, but the description adds no semantic information beyond the schema.

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 states a specific action: 'Return a data-block summary' and identifies the resource as 'blend_file'. It also notes the context of 'background Blender', which clarifies the headless operation. However, it does not explicitly differentiate from the sibling tool get_blendfile_summary_datablocks (without '_for_cli'), so the purpose is clear but sibling distinction relies on the name.

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 no guidance on when to use this tool versus the non-CLI sibling get_blendfile_summary_datablocks. It does not mention that this is the command-line variant or suggest using the non-CLI version in interactive sessions. There is no explicit when/when-not guidance.

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