inspect_region

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

With no annotations, the description carries the full burden and does disclose key side effects: it temporarily hides other objects and restores camera/visibility, and it caps output at 1..6 views and 256..1536 px. It omits failure modes, latency, and whether the restore happens on error, which keeps it below top marks.

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?

Short, front-loaded with the core capability, and each sentence adds information (defaults, side effects, precondition, size constraint). The telegraphic phrasing ('1..6', 'size is square pixels') is dense but not padded.

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 4-parameter tool with no annotations and no output schema, the description covers what the tool produces (PNG images), how it scopes them (selected parts, chosen views), and the state it disturbs and restores. Only error/permission behavior is left unaddressed.

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, and it does: parts (which objects are isolated), views (default Isometric/Top/Right, 1..6 count), size (square pixels 256..1536), and doc_name (must be active in 3D) are all explained. It stops short of enumerating valid view names beyond the three defaults.

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?

States a specific action (render 1..6 focused views of selected parts) and a concrete output (native MCP PNG images with world-geometry fingerprints). It differentiates itself from check_assembly as a visual supplement, but does not distinguish itself from siblings like inspect_part, get_view, or preview_alignment.

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?

Provides a precondition ('Requested document must be active in 3D') and a use-case link ('supplements check_assembly'), which gives implied guidance. It never says when to prefer this over inspect_part or get_view, or when not to use it, so the agent must infer alternative selection.

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