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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false) by disclosing what survives a rename (IDs, artwork, historical revisions), the cost model ('for free'), the optimistic-concurrency guard via expectedName, and the downstream effect that re-sync refreshes the exported display name. This is exactly the mutation-relevant context annotations can't provide.

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, no waste, front-loaded with the action and cost, followed by the safety mechanic and preservation guarantees. Every clause earns its place.

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 non-idempotent mutation tool with no output schema, the description covers cost, concurrency behavior, and preservation/sync side effects. It stops short of describing failure/error behavior or the return value, but is otherwise complete enough to call 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?

Schema coverage is only 50% — packId and componentId are documented but name and expectedName are not. The description compensates by explaining expectedName is the component's CURRENT name used as a stale-edit guard, though the new-name parameter is left to inference.

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 (Rename) and resource (an owned UI component) and adds a distinguishing constraint ('owned', 'for free'). An agent can immediately tell this apart from save_ui_component_defaults, replace_ui_component_png, and revise_ui_pack_png in the sibling list.

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 clear operational context — 'Supply its current name as expectedName to reject stale edits' — which tells the agent how and when the call is safe to make. It does not, however, name alternative tools or state when another sibling should be preferred instead.

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