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

With no annotations provided, the description carries the behavioral burden and does disclose key effects: mail acceptance stops immediately and messages become unreadable. It stops short of stating whether the deletion is permanent or irreversible, which is important for a destructive operation, but the core impact is clear.

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, front-loaded with the action and its immediate consequence, followed by a use-case cue. There is no filler and 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 simple one-parameter destructive tool with no output schema, the description covers purpose, immediate effects, and a usage context. It leaves a minor gap around irreversibility and recovery, but the essential information an agent needs to select and call it is present.

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 read_token parameter is fully documented in the schema. The description adds no parameter-specific detail, so the baseline 3 is appropriate when the schema already does the work.

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 and resource ('Delete an inbox') and immediately clarifies the consequence, so the agent knows exactly what operation is performed. It does not explicitly differentiate itself from sibling tools like create_inbox or list_messages, which keeps it from 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?

It gives a clear usage context: 'Use it when you are done with a signup.' That tells the agent when to invoke it, but there is no guidance on when not to use it or which sibling to use for related cleanup scenarios.

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