chromium-cookies

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

With no annotations, the description carries the burden. It discloses that HttpOnly cookies are included, the actions are destructive (e.g., 'clear removes ALL browser cookies'), and failure cases (non-Chromium device, missing params). It also describes return values for each action. Missing details on idempotency or rate limiting, but covers major behaviors.

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 well-structured with a clear introduction, bulleted action list, usage guidance, return types, and failure conditions. It is front-loaded with the core purpose. A minor reduction for length, but every sentence serves a purpose.

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 11 parameters, 4 actions, no output schema, and no annotations, the description covers purpose, usage, parameter roles by action, return values, and failure conditions. It lacks details about the format of returned cookie objects, but overall provides sufficient context for an agent to use the tool correctly.

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 coverage is 100%, so baseline is 3. The description adds value by grouping parameters per action (e.g., 'action="get" (url?)... defaults to the active page'), which provides context beyond the schema's individual parameter descriptions. It clarifies which parameters apply to which actions.

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 ('Read and write') and resource ('cookies of a Chromium (CDP) app'), and enumerates four distinct actions (get, set, delete, clear). It clearly distinguishes the tool's scope from siblings like 'chromium-storage' which handles other storage types.

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 explicitly says when to use the tool: 'Use when seeding an authenticated session before a flow... or asserting cookie state after one.' It also notes Chromium-only requirement and failure conditions. However, it does not mention alternative tools for related tasks (e.g., localStorage), leaving some ambiguity.

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