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

With no annotations to fall back on, the description carries the full burden and does it well. It discloses the CDP-based read path, the fallback to document.cookie with its httpOnly limitation, and the auto-selection behavior for pageId. These are non-obvious behavioral details that an agent needs before invoking the tool.

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 focused sentences with no filler. The core purpose and mechanism come first, followed by the fallback behavior and then the most important parameter guidance. 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 DevTools utility with no output schema, the description covers the mechanism, the returned cookie attributes, the fallback limitation, and pageId selection. A small gap is that it does not point to how to obtain a pageId if auto-selection is not desired, but the schema's 'auto-picked' note partially mitigates this.

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 baseline is 3. The description adds little beyond the schema: it repeats the auto-pick behavior already in the pageId schema description and does not elaborate on udid or socket. No compensatory parameter detail is needed because the schema is already complete.

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 action ('Get cookies for a page on the device'), the mechanism (CDP Network.getCookies), and the precise data returned (httpOnly, secure, sameSite, domain, path, expiry). This clearly distinguishes it from related DevTools siblings like console logs, captured network traffic, DOM inspection, and the iOS Safari cookies counterpart.

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 gives clear usage context ('useful for debugging auth/session state') and practical guidance on omitting pageId to auto-select the visible page. It does not explicitly say when not to use it or name alternatives, so it falls short of a 5 but is clearly more than minimal.

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