Update template variables

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

Annotations already declare `idempotentHint: true` and `destructiveHint: false`. The description adds 'global' scope but does not clarify whether the update replaces or merges with existing variables. With annotations covering safety, the description provides marginal extra behavioral context.

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, clear sentence with no extraneous information. It is front-loaded and efficient, earning its place without waste.

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 simple input schema (one parameter), presence of annotations, and no output schema, the description is minimally adequate. However, it could be more complete by specifying the update behavior (replace vs. merge) and the impact on dependent templates.

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 coverage is 100%, and the description does not add meaning beyond the schema. The schema already defines the 'variables' parameter as an object with string key-value pairs. The description simply restates 'Variables to set', which provides no additional semantic value.

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 'Update global template variables' clearly specifies the action (update) and resource (global template variables). It distinguishes itself from sibling tools like `arcane_template_get_variables` (retrieval) and `arcane_template_update` (which might update other template properties). However, the term 'global' could be clarified, but overall it's specific and unambiguous.

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 provides no guidance on when to use this tool versus alternatives, such as when to update template variables vs. using `arcane_template_update` for other template changes. It lacks context about prerequisites or scenarios where this tool is appropriate.

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