update_text_style

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

Beyond the minimal readOnly/destructive annotations, the description discloses a significant side effect: 'A new font is loaded before assignment.' It also specifies unit semantics (AUTO omits value) and states the return shape '{ ok, styleId, name }', giving a clear behavioral model.

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 front-loaded with the core action and each sentence covers a distinct aspect: purpose, optionality, side effect, units, usage, and return. There is no filler or 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?

For a 7-parameter tool with no output schema, the description covers purpose, usage, update semantics, units, and return value. It lacks error handling or permission requirements, but those are not essential for correct invocation.

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?

With only styleId documented in the schema (14% coverage), the description compensates by explaining optionality of every field ('Any of name / fontName / fontSize / lineHeight / letterSpacing / description may be omitted to leave unchanged') and detailing valid units for lineHeight and letterSpacing. It doesn't fully describe nested structures, but it adds meaningful semantics beyond the 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 opens with 'Update an existing text style (typography token) by id,' which names the specific verb, resource, and primary parameter. It also distinguishes from create_text_style by noting 'existing' and later 'instead of creating a duplicate.'

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 explicitly states when to use the tool: 'Use this to keep a shared style in sync with code instead of creating a duplicate.' It clearly implies the alternative of creating a duplicate style, but it doesn't name sibling tools like create_text_style or apply_style_to_node.

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