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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The sentence 'Does not change the design' merely restates those annotations rather than adding new context (no auth requirements, no side effects on the client session, no rate limits).

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 short sentences, front-loaded with the action and resource, with no filler. The second sentence is mildly redundant given the annotations, but it is cheap and unambiguous.

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, return values need not be described, and a single-parameter read tool with full annotation coverage is nearly complete. The only real gap is the absence of when-to-use routing against the many sibling design tools.

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?

Only one parameter with 100% schema description coverage, so the schema already fully documents projectId including its UUID format and pattern. The description's 'saved design belonging to the connected account' adds nothing beyond the schema text, making baseline 3 the correct ceiling.

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 pair (read and preview) and resource (saved design), and names the sibling-tool distinction implicitly by scoping to a single design identified by projectId. It stops short of explicitly contrasting with list_saved_designs/save_design, but an agent can still tell what this does.

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?

No when-to-use guidance and no alternatives named. The phrase 'belonging to the connected account' hints at a scope prerequisite, but nothing tells the agent when to pick open_design over list_saved_designs or list_design_options.

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