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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known. The description still adds value by stressing permanence ('removes the notification from the user's history entirely') and documenting failure semantics (error if the notification doesn't exist or isn't owned by the caller). It stops short of noting irreversibility/confirmation behavior explicitly, so 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?

Front-loaded with the core action, then the sibling contrast, then Args/Returns. Every sentence earns its place; the only friction is the verbose docstring-style Args/Returns block for a single-parameter tool.

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 no output schema, the description usefully documents the return shape (success/deleted_id on success, error string on missing/unauthorized). For a one-parameter destructive tool, deletion semantics, alternatives, and error cases are all 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 description coverage is 0% and there is one integer parameter, so the description carries the burden. It gives only a bare restatement ('ID of the notification to delete'), adding no format, source, or constraint detail beyond the parameter name.

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?

States a specific verb and resource ('Permanently delete a notification from the user's inbox') and immediately distinguishes the action from the sibling mark_notification_read by contrasting destructive deletion with non-destructive read-marking.

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?

Gives a concrete use case ('dismissing an old Weekly Recap row') and an explicit alternative with its selecting condition: 'marking it read is the non-destructive way to clear an unread badge.' When-to-use and when-to-use-something-else are both covered.

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