Set System Variable

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

The description adds value beyond the destructiveHint annotation by noting that type is auto-detected. However, it does not disclose other behavioral traits such as side effects, reversibility, or permission requirements, which are relevant for a destructive operation.

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 extremely concise at only two sentences, with the purpose front-loaded. Every sentence adds necessary information: the action and a guidance note, with no redundancy or filler.

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?

Given the tool has two parameters, destructive hint, and no output schema, the description covers the essential aspects. It could be improved by mentioning the return value (e.g., success indicator) or error handling, but it is largely complete.

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?

The schema already describes both parameters, but the description adds the key insight that type detection is automatic, complementing the anyOf type definition. This helps the agent understand that no explicit type specification is needed.

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 ('Set') and the resource ('system variable value'). The mention of type auto-detection and reference to list_system_variables provide additional specificity, distinguishing it from sibling tools like set_value.

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 advises using list_system_variables to see available variables, offering clear context for when to use this tool. However, it does not explicitly exclude alternatives or state when not to use it, which would make it stronger.

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