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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower, yet the description still adds real behavior: the empty-list case and the unauthenticated failure mode. This is exactly the kind of context annotations can't express.

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, zero filler, and the scope-defining phrase ('YOUR private design systems') is front-loaded. Each sentence carries distinct information: identity/scope, then consumption path, then edge behavior.

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?

No output schema exists, so the description correctly compensates by describing the return shape (name + slug) and the empty-list outcome. Nothing an agent needs in order to call and use this tool 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?

Zero parameters, which is the baseline for a 4. The description also clarifies the shape of each returned item (name + slug), which is the only 'parameter-like' semantic an agent needs to know to consume the output correctly.

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?

Specific verb (List) plus a precisely scoped resource ('YOUR private design systems (BYODS) — the sites you decoded into your own/your team's scope'). This cleanly separates it from get_design_system (fetch a single system) and from generic listing siblings. An agent knows exactly what this returns without opening any schema.

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?

Explicitly tells the agent what to do with the output: 'pass the slug/name to get_design_system or get_product to build against it,' naming the two natural follow-up tools. It stops short of a full when-to-use/when-not statement against the broader catalog, but the routing intent is clear.

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