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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true), so the bar is lower. The description adds one genuinely useful behavioral fact — the page re-flows on both desktop and phone — but says nothing about whether the moved widget's position persists, what happens to siblings' ordering, or what the call returns.

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 with the core operation front-loaded and no filler. The reflow sentence earns its place as side-effect context, though it could be slightly more precise about what 're-flows' means for the agent.

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 three-parameter mutation whose schema is fully documented and whose annotations cover safety, the description is nearly sufficient. The main omission is that it doesn't tie the page parameter to list_pages or the widget_id to get_page, forcing the agent to read the schema for that dependency.

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 description coverage is 100%, with all three parameters documented including the "after:<widget id>" syntax and defaults, so the schema does the heavy lifting. The description's restatement of top/bottom/before/after adds marginal meaning beyond the schema, so baseline 3 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?

Names a specific verb (move) and resource (widget) and enumerates the target positions, so the operation is unmistakable. It doesn't explicitly distinguish itself from siblings like update_widget or resize_widget, which is the only gap.

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?

Usage is implied by the verb and the enumerated positions (top/bottom/before/after), but there is no explicit when-to-use guidance, no mention of when to prefer update_widget, and no stated preconditions such as needing the widget id from get_page or the page slug from list_pages.

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