create_variable

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

Annotations already indicate readOnlyHint=false, idempotentHint=false, destructiveHint=false. The description adds only the non-idempotence note, which repeats annotation context. No additional behavioral details (e.g., side effects, rate limits, required permissions) are provided.

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 includes a banner prefix and three statements that essentially repeat the same idea. It could be consolidated into a single clear sentence without losing meaning. It is not excessively long but contains 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?

No output schema exists, so the description should clarify what the response contains (e.g., created record ID). It also does not address the fact that the input schema has no required fields, leaving ambiguity about minimal viable input. The tool is a create operation, and the missing post-creation context reduces completeness.

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?

Input schema has 100% description coverage, so the baseline is 3. The description does not elaborate on parameters beyond the schema; it merely repeats the action. No extra meaning or usage hints for fields like 'tag', 'name', 'format', 'content', or 'listids'.

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?

Description states verb 'creates' and resource 'variable' (personalization). It is clear but includes redundant phrasings ('Create a Variable', 'Creates a new record', 'Create a personalization variable'). Does not explicitly differentiate from sibling tools like edit_variable or list_variables, but the name and context make it reasonably specific.

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 a usage warning about non-idempotence ('Not idempotent — calling twice may create duplicates'), which is helpful. However, lacks guidance on when to use this vs. other variable tools (e.g., edit_variable or list_variables), and no prerequisites or success criteria are mentioned.

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