Copies cookies from source profile to target profile.

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the write nature is covered. The description adds a genuinely useful side-effect disclosure beyond the annotations: existing cookies in the target profile are overwritten. It omits prerequisites (locked/running profile behavior) and what happens when the source has no cookies, so it is not a 5.

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 tight sentences, action first and the important side effect second. Every sentence earns its place and there is no bloat or redundancy.

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 small mutation tool with no output schema and full schema coverage, the essential operation and its overwrite side effect are covered. However, prerequisites and edge-case behavior (missing source cookies, locked profiles) are absent, leaving the definition only minimally adequate.

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 profileId, workspaceId, and targetProfileId are already documented in the schema, including the -1 default for workspaceId. The description adds nothing about parameter usage or constraints, so the baseline 3 applies.

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 (copies) and resource (cookies) plus the direction (source profile to target profile), so the core action is unambiguous. It does not explicitly distinguish itself from the adjacent import_cookies/export_cookies siblings, which an agent might otherwise confuse with it, so it stops short of a 5.

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?

There is no guidance on when to use this tool versus the obvious alternatives (import_cookies, export_cookies, run_cookie_robot). No prerequisites are stated, such as whether source/target profiles must be stopped or unlocked. The agent gets no routing help.

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