light_create_directional

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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the agent knows this is a mutating operation. The description adds the 'target' and 'parallel rays' context, but does not explain any side effects, whether it creates an additional target object, or what the destructiveHint implies.

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 a single bilingual sentence with no filler. The key purpose is front-loaded, and the sunlight analogy is brief and useful.

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 creation tool with five optional parameters and no output schema, the description is mostly sufficient. It explains what is created but could be more complete by noting how it differs from light_create_sun and what the destructive annotation implies.

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 description does not need to explain parameters. It adds no special meaning beyond the schema, but the baseline of 3 applies because the schema already carries the full semantic burden.

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 names a specific verb and resource: 'Create a target Directional light - parallel rays like the sun.' This distinguishes it from sibling light creators such as light_create_omni, light_create_spot, light_create_sun, and light_create_area.

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?

No guidance is given for when to choose this tool over related sibling tools. In particular, saying 'like the sun' creates potential confusion with light_create_sun, and no alternative or exclusion criteria are mentioned.

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