set_data_layer_initial_runtime_state

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

Annotations already cover safety (readOnly=false, destructive=true, idempotent=true), so the bar is lower. The description adds valuable context beyond them: instance creation from the asset if missing, headless/no-PIE behavior, deferred effect on streaming, and a full Returns block that compensates for the absent output schema.

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 front-loaded sentences followed by a compact Returns block; every element carries information and nothing is padded.

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 mutating WP data-layer tool with no output schema, the description covers the effect timing, the precondition and its error behavior, instance auto-creation, and the full return shape. Nothing an agent needs to invoke it correctly is missing.

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 100%, so the schema already documents all three parameters. The description restates the state enum values and the create-if-missing behavior but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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 (Authors/sets) and resource (initial runtime state of a runtime data layer's instance), and distinguishes it from the live-runtime sibling by emphasizing 'initial' and 'takes effect when the level streams in.' An agent can tell it apart from set_data_layer_runtime_state without opening either 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 clear usage context and a precondition: 'Headless authoring (no PIE)', the effect timing ('takes effect when the level streams in'), and the requirement of a World Partition map with an 'honest error otherwise.' It stops short of explicitly naming the live-runtime alternative as a when-to-use exclusion.

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