sample_volume

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

With no annotations the description carries the full burden, and it does disclose non-obvious behavior: the VDB SDF returns its background (band width) outside the narrow band rather than true distance, and the call 'adds no node to the scene'. It omits return-shape and any cost/performance context, so it is strong but not exhaustive.

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?

Front-loads the core capability in one sentence, follows with a motivating example, then a compact Args list — every block earns its place. The example sentence is slightly convoluted but the structure is sound.

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 7-parameter tool with no annotations and no output schema, the definition covers purpose, usage scenario, side effects, and every input's meaning. It hints at the summary (limit/bin/threshold) but never describes the actual return structure, which is the one remaining gap given no output schema exists.

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 its Args block documents all seven parameters with real meaning: fields as the 'name' attribute, positions in world space, from_node overriding positions, limit applying to values but never the summary, bins as count-or-edges, and threshold as an above-value count. This fully bridges the schema gap.

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 verb and resource ('Read named volume fields') plus the two supported point sources ('at world positions, or at another SOP's points'). This cleanly separates it from sample_geometry and compare_volumes without the agent opening any schema.

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 concrete scenario ('what does the collision SDF read where the particles are') mapped to a specific parameter (from_node), and clarifies the from_node-vs-positions choice. It stops short of naming when NOT to use it or pointing to get_volume_info / compare_volumes as alternatives.

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