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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral detail: the payload is exhaustive ('every design token') and DESIGN.md is capped at 4000 characters, which tells the agent to expect truncation. It does not say what happens if the slug is unknown or whether output is cached, keeping it just short of a 5.

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?

Two sentences, both earning their place: the first front-loads what is returned, the second handles usage and routing to the alternative. No filler or repetition of the title.

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?

There is no output schema, but the description compensates by enumerating the returned token categories and the 4000-character DESIGN.md cap. With only one required, fully documented parameter and complete annotations, an agent has everything needed to call it correctly.

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 single slug parameter is documented in-schema as 'exactly as listed by list_styles'. The description adds nothing about the slug (no format, case sensitivity, or error behavior), so the schema does all the work and the baseline 3 applies.

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 and resource ('Returns every design token of one extracted brand style') and then enumerates the token categories returned (colours, fonts, spacing, radii, CSS variables, DESIGN.md). It also explicitly distinguishes itself from the sibling get_component_styled, so an agent can pick between them without opening schemas.

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?

Gives both a positive use case ('theme your own code or set up a design system') and an explicit alternative with its selecting condition ('use get_component_styled when you want one specific component already paired with the style'). Nothing is left to inference.

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