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

With no annotations provided, the description carries the full behavioral burden and succeeds: it discloses the primary CDP mechanism, the fallback to document.cookie, the limitation that the fallback only returns non-httpOnly cookies, and the auto-pick behavior for omitted pageId. This gives an agent an accurate mental model of execution and limitations.

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 deliver the tool's purpose, returned fields, fallback behavior, and page-selection semantics with no filler. The most decision-relevant information is front-loaded.

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?

Despite having no annotations and no output schema, the description is self-sufficient: an agent knows what the tool returns, how it behaves under failure/fallback, when to use it, and how page selection works. Nothing critical is missing for correct invocation.

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?

The input schema already has 100% parameter coverage with rich descriptions, especially for pageId. The description adds framing about page auto-selection and the Web Inspector path, but it does not materially add parameter meaning beyond what the schema already provides, so the baseline of 3 is appropriate.

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 uses a specific verb and resource: 'Get cookies for a Safari page on an iOS device via the Web Inspector (Page.getCookies)'. It enumerates the returned cookie fields, making the tool's scope unmistakable and clearly distinct from cookie-writing or cookie-clearing siblings.

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 identifies a concrete use case ('useful for debugging auth/session state') and explains the automatic page selection behavior when pageId is omitted. It does not explicitly state when not to use the tool or name alternative cookie tools, so it stops short of full exclusion guidance.

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