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

The description adds substantial behavior beyond the readOnly and idempotent annotations: it explains that displaying a view has no approval, authentication, payment, or state-change side effect, and that hosts without UI still receive readable data. This is exactly the kind of safety and environment behavior an agent needs.

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?

The description is three tight sentences, front-loads the core purpose, then adds the critical non-action constraint and host fallback. Every sentence carries useful information without repetition.

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?

Given the rich schema and the presence of an output schema, the description supplies the missing behavioral context: token provenance, non-side-effect semantics, and fallback behavior on non-UI hosts. Nothing essential for correct invocation appears to be 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%, and the schema already defines the oneOf variants, required fields, and kind enums. The description adds some useful provenance semantics by requiring presentation tokens and request IDs returned by Darwin, but it does not explain how each parameter maps to the view kinds or clarify thread/message/cursor usage.

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 states a specific verb and resource: display a read-only view. It names the view categories (agent matches, approval/authentication/payment requests, completed output) and clearly distinguishes itself from action-oriented siblings by stating it never approves, authenticates, pays, or changes state.

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?

It clearly scopes usage to presentation tokens and request IDs returned by Darwin, and explicitly rules out using this tool for approvals, authentication, payment, or state changes. It does not explicitly name alternative siblings such as act or navigate for those actions, leaving a small gap.

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