Styles: Set Current Text Style

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

Goes well beyond the sparse annotations (only readOnlyHint=false) by disclosing that this mutates $TEXTSTYLE, that the effect propagates to subsequent text/mtext creation on both engines, and that an unknown style name is rejected. Return fields are stated, though an output schema already covers them.

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?

Three short clauses with the core action front-loaded and zero filler; each clause (effect, precondition, return) earns its place.

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 one-parameter mutation with annotations plus an output schema, the description covers the mutation target, scope of effect, failure condition, and return fields. Nothing an agent needs to call it correctly is missing.

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% (baseline 3), and the description adds real semantic value: the name must reference a style the drawing already holds or the call is refused, constraining the valid domain of the single parameter.

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 (Set) and resource ($TEXTSTYLE / text style), then explains the downstream effect on entity_create_text / entity_create_mtext. This distinguishes it from textstyle_list and textstyle_create by describing what 'current' actually means on both engines.

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 refusal clause ('Refuses a style the drawing does not hold') implies a precondition that the style must already exist, which points toward textstyle_create first. However, no sibling is named as an alternative and there is no explicit when-not guidance.

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