Roblox MCP

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

Without annotations, the description must carry behavioral disclosure. It provides feature-tier context via [PRO] labels, implying some features may be gated. However, it lacks critical behavioral details: return format (what does 'query' return?), error handling (timeout behavior for 'wait_for_child'), performance characteristics (descendant searches can be expensive), or side effects.

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?

Dense but efficient single-sentence structure. Front-loads the verb ('Query') and resource, followed by categorized action lists. Every phrase maps to specific functionality. No redundant prose, though the density sacrifices some readability.

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 18 parameters and high schema coverage, the description doesn't need to re-document inputs. However, lacking both an output schema and return value description in prose, the agent cannot predict what data structure the tool yields (instance references, full property bags, paths?), which is a gap for a complex query tool.

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?

With 100% schema description coverage, the structured data fully documents all 18 parameters. The description adds no additional semantic context (syntax examples beyond schema, validation rules, or dependency constraints between parameters like 'action' and 'path'). Baseline 3 is appropriate.

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 specific query actions (get, children, find_child, etc.) and identifies the resource (Roblox instances). The [PRO] grouping distinguishes capability tiers. It differentiates from siblings like 'mutate_instances' by emphasizing read/query operations, though it doesn't explicitly contrast with 'spatial_query'.

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?

Lists available actions but provides no guidance on when to select this tool versus siblings like 'spatial_query' or 'workspace_state'. No mention of prerequisites, execution order, or when specific actions (e.g., 'wait_for_child' vs 'find_child') are appropriate.

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