setup_extract_cookies

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

With no annotations, the description carries the transparency burden. It discloses a non-obvious side effect: macOS triggers a Keychain prompt. It also warns that a system prompt may appear, which is valuable behavioral context beyond the tool's basic function.

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 with no filler. The first states the action; the second delivers the critical warning and prerequisite. Every word earns its place and the most important caveat is highlighted with 'IMPORTANT'.

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 zero-parameter tool with no output schema, the description is complete: it states what is extracted, where from, and the user-facing side effect and prerequisite. No additional context is needed for an agent to safely invoke it.

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 tool has zero parameters, so there is no parameter schema to elaborate on. The baseline for 0 parameters is 4; the description instead clarifies preconditions, which is appropriate given there is nothing else to document.

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 ('Extract') with a clear resource ('Figma session cookies from Chrome'). It unambiguously distinguishes this tool from sibling setup tools like status, select_account, and save_pat.

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 provides clear usage instructions: confirm the user is logged into figma.com in Chrome and warn about a system prompt. It does not explicitly mention alternatives, but the given precondition is directly actionable and sufficient for this setup context.

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