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

With no annotations, the description carries the burden and does disclose real behavior: ordering ('most recently deleted first') and per-item contents (who deleted it, restorableUntilEpochMillis). It omits auth/permission requirements and what happens when the trash is empty.

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 dense sentences that front-load what the list contains, followed by purpose. The trailing 'Takes no arguments' is an inaccurate throwaway that costs a point but does not bloat the definition.

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, yet the description usefully previews the fields an agent will act on. Given zero annotations and a read-only list tool, the only meaningful gaps are pagination/result-size limits and permission context.

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%, so the three optional params (token, agentName, agentModel) are already documented and the description needn't repeat them. However, 'Takes no arguments' is an over-broad claim that could lead a header-constrained client to skip the token param; it also adds no semantic value, so only the baseline 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+resource+scope: designs in the trash that are restorable, with a note on scope ('ones you deleted, or ones you own'). An agent can distinguish this from ui_builder_list_designs and ui_builder_restore_design without opening a 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?

Gives two concrete use cases: undoing an ui_builder_delete_design you regret, or auditing what a cleanup removed. It names the delete sibling but never routes to ui_builder_restore_design, the natural next step, so it stops short of explicit when/when-not guidance.

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