set_text_style

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

With no annotations, the description carries the full burden of disclosing behavior. It indicates a mutating operation on the current selection and mentions a return value, but it does not say what happens to unspecified properties (e.g., whether null leaves them unchanged), whether the action is reversible, or what side effects occur. This is a meaningful gap for a formatting mutation tool.

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 well-structured with a clear one-sentence purpose, an organized Args list, and a Returns line. Each parameter line earns its place, and there is no redundant or filler content.

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?

The description covers the purpose, all parameters, and the return value, and an output schema exists, so return details are not critical. However, it lacks context around when this tool is appropriate relative to style-related siblings and what happens to formatting properties not specified in the call. These gaps are significant for a tool operating on the current selection.

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?

Despite the schema having 0% description coverage, the description compensates by adding meaning to every parameter: doc_id provenance, font name example, font size unit, and color hex format. Bold/italic/underline get only tautological one-word descriptions, but overall the description provides useful guidance beyond the raw schema.

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 uses a specific verb and resource: 'Set character formatting for the current selection.' It clearly identifies the object (character formatting) and scope (current selection), which distinguishes it from paragraph- or page-level styling tools. However, it does not explicitly differentiate itself from the similarly named sibling set_char_shape, so it stops short of full sibling differentiation.

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 gives no explicit guidance on when to use this tool versus alternatives like set_paragraph_style or set_char_shape. It implies the need for a current selection, but it never states prerequisites, exclusions, or a decision rule. The agent is left to infer the appropriate scenario from the tool name and sibling list.

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