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

Annotations already declare destructiveHint=true and idempotentHint=false, but the description adds genuinely new behavioral context: the deletion is permanent/irreversible and the associated time entries are NOT cascaded away. It also mandates user confirmation. It stops short of stating permission requirements or exactly what else references the invoice.

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?

Three short sentences, no filler, with the destructive/permanent nature and cascade behavior front-loaded ahead of the confirmation instruction. Every sentence earns its place.

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 one-parameter destructive tool with an output schema and full annotation coverage, the description supplies exactly the additional facts an agent needs: irreversibility, non-cascading of time entries, and a confirmation requirement.

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% and the single parameter is fully documented in the schema with a format example (INV-2026-004), so the description adds no parameter meaning beyond it. Baseline 3 is correct when the schema does all the lifting.

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+resource ('Permanently delete an invoice record') and immediately clarifies scope by saying the time entries stay, which separates it from the sibling delete_entry that removes time data. An agent can distinguish it from delete_entry without opening either schema.

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 an explicit precondition for invocation ('Confirm with the user before calling this'), which is the key usage constraint for a destructive tool. It does not name an alternative action (e.g., marking paid or voiding) that would avoid deletion, so it falls short of full when-not guidance.

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