Read material properties at runtime for the first mesh matching a CSP mesh filter, returning ksEmissive, ksAmbient, ksDiffuse, and ksAlphaRef by default.
Read material properties at runtime (first mesh matching a CSP mesh filter, e.g. 'material:MyMat'). Default properties: ksEmissive, ksAmbient, ksDiffuse, ksAlphaRef.
| Name | Required | Description | Default |
|---|---|---|---|
| filter | Yes | ||
| properties | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden; it does disclose two important behaviors — only the FIRST matching mesh is read, and which properties are returned by default. It omits what happens when no mesh matches the filter (error vs. empty result) and never states the operation is side-effect free, leaving meaningful gaps for a mutation-adjacent runtime tool.
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?
Two compact sentences, front-loaded with the core action and scope, followed by the default return set. Nothing is wasted and the filter example is placed exactly where it is needed.
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 2-parameter tool with no output schema and no annotations, the description covers purpose, selection scope, and default return fields. It still lacks failure/no-match behavior and the semantics of the properties argument, which are the two things an agent must know to call it correctly.
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 coverage is 0%, so the description must compensate. It handles 'filter' well with the 'material:MyMat' example identifying the CSP filter syntax, but the 'properties' parameter is only indirectly referenced via 'Default properties' — it never says that passing properties overrides that default list or what form values take.
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 gives a specific verb+resource ('Read material properties at runtime') and defines the selection scope precisely: the first mesh matching a CSP mesh filter. It implicitly contrasts with the sibling ac_material_set (write) but never names it, so differentiation is inferable rather than explicit.
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?
Usage is implied by 'at runtime' and the filter example, but there is no explicit statement of when to prefer this over ac_material_set or ac_get_state, and no prerequisite/conditions described. An agent can infer purpose but is given no routing guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.