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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine context beyond that: the list is curated (not user-generated), items carry preview images, and the ids are consumed by the `design` tool. It does not discuss result volume or pagination, but the output schema and limit/offset params cover that.

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 sentences, front-loaded with the purpose, then the trigger, then the fallback. Every sentence carries information the agent needs to route correctly.

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?

An output schema exists, so return values need no explanation, and annotations cover the safety profile. The description supplies exactly the missing pieces: what the items are, when to fetch them, and how the resulting id is used downstream.

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 description coverage is 100%, with limit and offset fully documented in the schema with defaults and bounds. The description adds no syntax or semantics beyond that, so 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 ('List curated app styles') and adds what the resource actually is ('and their preview images'), distinguishing it from sibling list tools like list_components and list_projects. An agent can tell instantly that this returns style references, not components or projects.

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 a concrete trigger ('when your user asks for a look such as Airbnb, brutalist, or dark fintech') plus the downstream action ('pass the closest reference's id as referenceId to design'). It also names the alternative path explicitly ('without a reference, the agent picks a style'), so the agent knows both branches.

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