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

Annotations already set destructiveHint=true and readOnlyHint=false. The description adds valuable behavioral detail beyond those flags: categories not mentioned are preserved, resetCategories removes overrides, and categoriesJson cannot remove an override. This is exactly the kind of non-obvious mutation behavior an agent needs to know.

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?

Four short sentences, each carrying a distinct piece of information: scope, merge behavior, reset mechanism, and valid categories. No filler or redundancy; the most important behavioral constraint is front-loaded.

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?

With only 2 parameters and no output schema, the description fully covers both parameters, valid values, merge behavior, and the destructive reset path. An agent can construct a correct call and understand the consequences without needing additional context.

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 meaning beyond the schema by enumerating valid categories and explaining the override/reset distinction, which the schema's terse parameter descriptions do not convey. This compensates for the lack of enums in the schema.

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 opens with a specific verb-resource pair: 'Set YOUR notification preferences for one or more categories.' This clearly distinguishes it from read-style siblings like get_notification_preferences and get_my_permissions.

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 explains the merge semantics ('Categories you do not mention keep their current setting'), the role of resetCategories, and the fact that categoriesJson can only create overrides, not remove them. It does not explicitly name alternative tools, but the usage context is clear enough for an agent to know when to call it.

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