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

Annotations already mark destructiveHint=true and readOnlyHint=false, but the description adds useful behavioral context: the deletion is permanent and also removes stored contact snapshots. This goes beyond the annotations by specifying exactly what gets destroyed. No contradiction with annotations.

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?

A single, front-loaded sentence that conveys the action, the resource, and the consequence. No unnecessary words or repetition.

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 simple delete tool with one parameter, the description is sufficiently complete. It clarifies the destructive scope (permanent deletion of list and snapshots) and is consistent with annotations. No output schema is provided, so return values are not required. Minor addition could include a warning about irreversibility, but 'permanently' already conveys that.

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?

The schema provides 100% coverage for the only parameter, listId, with its description 'The unique identifier of the contact list.' The description adds no additional parameter-level meaning, so the baseline of 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 clearly states a specific verb+resource: 'Permanently delete a contact list' and adds the scope that it also deletes 'stored contact snapshots.' This distinguishes it from sibling tools like contact_lists-create/get/update/list and company_lists-delete by specifying the exact resource and effect.

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?

Usage is implied by the verb 'delete' and the permanent nature, but there is no explicit guidance on when to choose this vs alternatives (e.g., contact_lists-update, contact_lists-list) or any mention of prerequisites or exclusions. It gives clear context but no differentiation.

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