Update User Permission

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

With no annotations, the description carries the behavioral disclosure burden. It discloses a critical non-obvious behavior: replacement rather than merge, and instructs callers to send the complete desired resource. It does not mention authorization requirements or reversibility, but it does cover the most safety-relevant mutation semantics.

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 two sentences with no filler: the first names the operation, and the second highlights the key behavioral caveat. It is front-loaded and easy to parse.

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 the output schema exists and the input schema is fully documented, the description provides enough context for correct invocation, especially the replace-not-merge warning. The lack of any mention of required permissions or explicit differentiation from create_user_permission leaves a minor completeness gap, but the core behavior is well covered.

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 the baseline is 3. The description adds value by naming 'accountAccess' and 'containerAccess' within the user_permission object and clarifying that these must be the complete desired state, which supplements the schema's generic 'new access levels' wording.

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 clearly states a specific action ('Change a user's access') and a specific resource (Tag Manager account), which distinguishes it from sibling tools like get_user_permission, create_user_permission, and delete_user_permission.

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 conveys the update context by explaining that the request replaces existing access levels, implying it is for modifying an existing permission rather than creating one. It does not explicitly name create_user_permission as the alternative, so the guidance is clear but not fully explicit.

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