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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description needs to add context and it does: it discloses the cascade that all contained messages are destroyed and that the operation is irreversible. What it omits is behavior for the idempotentHint=true annotation — e.g., whether deleting already-removed or invalid account IDs succeeds silently or errors.

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?

Two short sentences, zero filler, with the destructive scope front-loaded before the irreversibility warning. 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 no output schema, the definition covers what matters most: what is destroyed, including nested messages, and that recovery is impossible. It is thin on permission requirements and on handling of nonexistent or already-deleted account IDs, which is the main remaining gap.

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% and the single 'accountIds' property is documented with a pointer to 'list_accounts', so the schema carries the parameter burden. The description adds no extra meaning such as batch limits, behavior on partially valid ID lists, or ordering of the array.

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 gives a specific verb and resource ('Permanently deletes GhosterMail mailboxes') and adds scope ('with all their messages'), which clearly separates it from create_accounts and the read/list siblings. It does not explicitly name a sibling it contrasts with, so it stops short of a 5.

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?

There is no when-to-use guidance: nothing says under what conditions a mailbox should be deleted, whether it must be empty first, or what alternative to use for disabling rather than destroying an account. The only directive content is the irreversibility warning, which is a caution rather than routing guidance.

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