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

Goes well beyond the annotations: discloses that changes apply instantly, that the call returns the resulting style, that style survives version restore, and enumerates error outcomes ('not_found', 'invalid_payload') including the invalid case of providing no field. This is rich behavioral context consistent with readOnlyHint=false and idempotentHint=true.

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?

Front-loaded with the core action, then enumerations, then side-effect and error notes. Dense but every clause carries information; the enumeration of values makes it longer than strictly necessary given the schema already lists them.

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?

With an output schema present it need not describe return shape, yet it still mentions the return value and pins down error codes, idempotent patch behavior, and versioning interaction. Nothing material for correct invocation 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?

The description restates the allowed values and adds genuinely useful meaning: the font-to-typeface mapping, the colour set, and the guidance that free-text colour requests must be mapped to the nearest of the five since no pure red/blue exists. That mapping rule is not derivable from the schema alone, though some content duplicates schema descriptions.

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?

Names a specific verb ('Change') and resource ('a resume's visual style') and enumerates the exact facets it controls (accent colour, layout, font). This clearly separates it from content-editing siblings like update_resume_section and from versions tools like create_resume_version.

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?

States the patch semantics ('Fields left out are preserved') and the scope boundary that style is not versioned ('history and restore leave it as is'), which tells an agent when styling is reusable across versions. It does not explicitly name an alternative tool, but the context for use is clear.

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