set_instanced_mesh

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

Adds important context beyond annotations: changes are runtime-only and lost on reload. Annotations already indicate destructiveHint=true, but description clarifies it's non-persistent, which slightly contradicts (see contradiction). Still, useful transparency.

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-loaded with main action and key warning about runtime-only. Slightly repetitive with two sentences on asking user, but still short and efficient.

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?

No output schema, but description explains purpose, temporary nature, and prerequisite (ask user). Missing details on edge cases (e.g., count exceeding instances), but schema covers parameters and context signals indicate high coverage.

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 100% with all parameters described. The description lists a few properties but does not add extra meaning beyond the schema, so baseline score of 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?

The description clearly states the action (Modify) and resource (InstancedMesh properties: count, visibility, frustumCulled). It distinguishes from siblings by specifying the runtime-only nature, which is unique among set_* tools.

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?

Explicitly instructs to ask the user first about runtime preview vs. persistent code change, repeated for emphasis. Provides clear guidance on when to use and what to clarify before proceeding.

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