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

Annotations already include destructiveHint=true and idempotentHint=true. The description adds valuable context by specifying that it removes stored bytes and that there is no undo through the API, which goes beyond the annotations and helps the agent understand the irreversible nature of the operation.

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?

The description is two concise sentences. It leads with the action, then provides the critical warning. Every word earns its place; no filler 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 operation with one required parameter and clear destructive annotations, the description covers the essential behavior. It doesn't mention return values or side effects beyond data removal, which is acceptable given the low complexity and absence of an output schema.

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%—both slug and vigil_key are fully documented in the schema, including the deprecation note. The description adds no extra parameter-specific guidance, but since the schema handles it fully, the baseline of 3 is appropriate.

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 the verb ('Delete'), the resource ('journal slot'), and the destructive consequence ('removes stored bytes with no undo'). It unambiguously distinguishes itself from sibling journal tools like get/put/list.

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?

While it does not explicitly name alternative tools or exclusion conditions, the destructive warning and the action verb clearly imply the intended scenario (permanent deletion). It lacks explicit routing to alternatives but the context is strong enough for an agent to select it appropriately.

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