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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds behavioral context about the semantic (non-visual) nature of the snapshot and the scope preference, which helps the agent understand what the tool will actually return and how traversal is constrained.

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?

Three sentences with zero filler. The purpose is front-loaded, the primary scope constraint follows immediately, and the alternative routing is saved for the end. Every sentence 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 moderately complex 9-parameter tool with a full schema and an output schema, the description covers the essential usage context: when to invoke, how to choose scope, and which sibling to prefer for web pages. The output schema handles return-shape details, so nothing an agent needs to call this correctly is missing.

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%, so the schema already documents all nine parameters. The description adds a brief scope recommendation ('Prefer scope=active; use scope=desktop only for cross-application discovery'), but this largely mirrors the schema's own scope description. It adds no deeper parameter meaning beyond what the schema already provides.

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 names a specific verb ('inspect'), a resource ('native desktop Accessibility/UI Automation semantics'), and a contextual trigger ('before clicking or typing'). It explicitly differentiates itself from browser_snapshot, so an agent can distinguish it from a key sibling without opening the 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?

The description gives explicit when-to-use guidance, prescribes scope=active as the default, limits scope=desktop to cross-application discovery, and names browser_snapshot as the preferred alternative for Chromium page DOM semantics. This is direct, action-oriented routing with no inference required.

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