Add a reference artifact

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

With no annotations, the description carries the behavioral burden. It usefully discloses that the artifact is 'held, not rendered', returns an artifactId, and is part of a 2-step lifecycle. It does not mention persistence, ordering constraints, or permission requirements, but the core observable behavior is clearly communicated.

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?

The description is focused and each sentence earns its place, including the return value and the concrete example. It is slightly dense with the phrase 'Instanced Manifestation' and the parenthetical lifecycle note, but remains efficient and readable.

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 simple 2-parameter tool, the description is largely complete: it covers the resource, the behavior, the intended use case, and the return value. It leaves minor questions about sourceUri applicability and any side effects, but does enough for an agent to select and 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 100% for the two parameters, so the schema already explains sourceUri and description. The description adds value by showing the intended content of the description parameter: 'this is what I want the presence to look like'. It does not add anything specific about sourceUri.

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 states a precise action: 'Adds a Gaussian splat artifact (or other content asset) to the substrate as reference material'. It also distinguishes this tool from siblings by explaining the artifact is 'held, not rendered', and positions it as step 1 in an add/retire lifecycle.

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?

The description gives explicit guidance: 'Use this to give spawnPresence something concrete to build from' and contrasts with 'describing appearance in prose'. The add/retire pairing also implicitly names retireArtifact as the opposite operation.

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