Stop a rental

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

Adds substantial context beyond the annotations: files remain reachable read-only for a limited retrieval window, the operation is safe to repeat, the return payload (rental_id plus STOPPING or later state), and the AMPLERUN_MCP_ALLOW_SPEND=1 gate that otherwise refuses the write. This is exactly the destructive/auth behavior an agent needs and annotations alone cannot convey.

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?

Four compact sentences, front-loaded with the core effect before the retrieval-window caveat and the auth gate. Each sentence carries non-redundant information, though the return-value sentence is slightly terse relative to the rest.

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 destructive, gated mutation with no output schema, the description covers effect, consequence window, idempotency, return shape, and the auth requirement. Nothing an agent needs to invoke it correctly is missing.

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 rental_id, reason, and idempotency_key are already fully documented in the schema. The description adds nothing parameter-specific, 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+resource ('Stop an AmpleRun rental') and immediately scopes the effect: the workload and its metering end. It is clearly distinguishable from siblings like get_rental or list_rentals, which are read operations.

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 verb and the noted idempotency ('Stopping again is harmless'), but it never explicitly says when to use this versus checking state with get_rental first, nor any prerequisites beyond the env-var gate. Adequate but leaves the when-to-use inference to the agent.

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