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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation, so the bar is lower. The description adds a real behavioral fact beyond them — registered keys only, guest keys cannot rent — plus the bot-handle constraint. However, for a rental that presumably incurs cost, it says nothing about charging, what happens to the bot during/after the borrow period, or the return payload.

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 WHEN clause is front-loaded and the required-key note follows, with a compact call example at the end. The opening 'Rent-a-Bot: borrow.' mostly restates the title and could be dropped, but nothing else is wasted.

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 an eight-parameter mutating rental tool with no output schema, the definition covers the handle prerequisite, auth requirement, and arg equivalence to rent_hire. It leaves out what success returns (a status handle? rental id?) and any billing or duration semantics, which matter for a paid borrow operation.

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%, so the schema already documents all eight parameters including the enum, ranges, and brief length limit. The description adds only that the args match rent_hire and demonstrates a minimal call with the required bot field. Baseline 3 is appropriate when the schema does the heavy lifting.

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 names a concrete verb and resource (borrow a house bot) and explicitly positions the tool as a shortcut for rent_hire scoped to the house pool, which lets an agent distinguish it from rent_hire and rent_house_pool. The 'Dead Brands' framing is unexplained jargon, but the operative purpose is 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?

A dedicated WHEN clause states the triggering condition (borrowing a house bot from the house pool) and the description names rent_hire as the general alternative this shortcuts. It also surfaces the prerequisite that the key must be registered. It stops short of stating when NOT to use it, but the routing context is explicit.

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