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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description doesn't need to restate those. The description adds the key behavioral constraint that stock content cannot be deleted, which is beyond the annotations. It also clarifies the operation is permanent, which reinforces the destructive nature. This adds value beyond the structured data without contradicting it.

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 sentences with no filler. The first sentence states the action and scope; the second provides a critical safety guideline. Every word earns its place, and the most important information (permanence, user-authored only) is front-loaded.

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 single-parameter delete tool with a full output schema and annotations covering destructive/idempotent behavior, the description is nearly complete. The only minor gap is that it doesn't describe what happens if the id doesn't exist or if the user lacks permission, but the output schema likely covers error responses. The 'pair with vault_get_rule' guidance compensates for potential misuse. A 4 is fair given the tool's simplicity.

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%: the only parameter 'id' is fully described as the Mongo `_id` of the vault document. The description adds that the id refers to a user-authored rule, which is a slight semantic enrichment, but the schema already carries the main meaning. Baseline 3 is correct because the schema does the heavy lifting and the description adds only marginal context.

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 states a specific verb ('Permanently delete'), a specific resource ('user-authored rule'), and identifies it by id. It also distinguishes from stock content deletion, which is a clear scope boundary. The title 'Delete a vault rule' is reinforced with the permanent and user-authored qualifiers, making the purpose unambiguous.

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?

The description explicitly instructs to pair with vault_get_rule first to confirm the target, which is a clear usage guideline. It does not explicitly name alternatives or when-not-to-use, but the sibling list includes vault_delete_character, vault_delete_item, vault_delete_spell, and the 'Cannot delete stock content' exclusion provides context. A 4 is appropriate because it gives actionable guidance but doesn't fully enumerate alternatives.

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