create_mass_entity_config

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

Annotations already declare the safety profile (write, non-destructive, not open-world), so the bar is lower; the description adds real behavioral context by disclosing that an existing config is loaded and re-saved (created:false) rather than duplicated. There is mild tension with idempotentHint:false, but the description describes behavior rather than asserting idempotency, so it is not a hard contradiction.

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 the core action and behavior, and every sentence contributes. The return fields are stated twice (once inline, once in a 'Returns:' block), which is a minor redundancy.

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?

With no output schema, the description correctly enumerates the return object, and with annotations covering the safety profile and full schema coverage on both params, an agent has enough to invoke it correctly. Only the workflow's prerequisites (e.g. package must exist) are left implicit.

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 config_name and package_path. The description references package_path/config_name as the target location but adds no format, validation, or default details beyond what the schema provides, making the baseline 3 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 a specific verb+resource (create a UMassEntityConfigAsset), its initial state (an empty list of Mass traits), and its destination (package_path/config_name), then saves it. It explicitly routes to siblings add_mass_trait and set_mass_spawner_entity_types, so an agent can distinguish it from the surrounding Mass tools without opening a 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?

Gives a clear workflow: create the config here, add traits with add_mass_trait, then link it with set_mass_spawner_entity_types. It also explains the alternative path when a config already exists. It stops short of stating when NOT to use it, so it's strong but not fully prescriptive.

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