Attach design systems to a project

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

With no annotations provided, the description carries the full burden of disclosing the tool's side effects. It clearly states that the operation replaces the entire current set, which is critical behavioral information. It also explicitly covers the 'detach all' behavior with an empty list, leaving no ambiguity about the mechanism.

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 two short sentences, front-loaded with the main purpose, and every phrase adds value. It avoids repetition and is immediately readable, making it an excellent example of concise, well-structured documentation.

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 simple two-parameter tool with no output schema, the description covers the main behavior, the replacement semantics, the empty-list special case, and how to correctly provide the parameter. No additional context is needed; the tool is fully specified for an agent to use 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?

The schema provides descriptions for designSystemIds (including the empty array behavior) but not for projectId. The description adds critical meaning to designSystemIds by instructing the user to 'pass every one you want kept,' which supplements the schema's note. While projectId is not elaborated, its role is self-evident from the name and context, so the description compensates adequately for the 50% schema coverage.

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 clearly states the action ('Set which design systems a project designs against') with a specific verb and resource. It distinguishes itself from sibling tools like 'create_design_system' (which creates a new system) and 'link_local_code' (which connects code), making its purpose unambiguous.

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 provides explicit instructions on how to use the tool: 'Replaces the current set, so pass every one you want kept. Pass an empty list to detach all.' This tells the agent exactly what to pass and handles the edge case. It doesn't name alternative tools, but no close alternative exists among siblings, so the guidance is sufficient.

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