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

With no annotations supplied, the description carries the full burden and does well: it declares irreversibility, names the concrete side effect (permanent data loss for the target ID), scopes the operation to the caller's private partition, and even gives the return shape. Gaps remain on failure modes (what happens for an unknown or already-deleted ID) and any permission or confirmation requirements.

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 compact sentences, front-loaded with the operation tag and the core action, followed by the return value and the side effect. Nothing is repeated or wasted, and the destructive warning lands before the agent commits.

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 description covers the action, the destructive consequence, and the return shape, which is nearly everything an agent needs. It stops short of describing error behavior for invalid or missing IDs, which matters more than usual for an irreversible delete.

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% with a single required parameter already described as "ID of item to delete." The description adds only that the ID targets a specific item in the private vault partition, which is slight reinforcement rather than new meaning, so the baseline 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?

States a specific verb and resource ("Irreversibly delete a specific item from your private vault partition") and the bracketed tag [PRIVATE WRITE - VAULT DELETE] reinforces scope. This distinguishes it cleanly from read/search siblings like vault_read and vault_query and from the write siblings vault_write_cell and vault_write_hypothesis.

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 delete semantics — an agent can infer this is the tool for removing an existing vault item rather than reading or writing one. However, there is no explicit when-to-use/when-not guidance, no statement of prerequisites (e.g., whether the ID must already exist, whether confirmation is expected), and no routing to an alternative if the intent is something other than deletion.

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