Get rental status and access

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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds genuinely new behavioral context: access data (endpoints, SSH host-key fingerprint, ready-made command, per-rental API key) is only returned while RUNNING or during a limited post-STOPPED window. That temporal constraint and the disclosure of sensitive credential material go well beyond the structured fields and directly affect how an agent should call and handle the result.

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?

Front-loads the core resource and its fields, then adds the conditional access behavior and the sibling pointer. Dense but every clause carries information; only the run-on sentence about access is slightly awkward to parse.

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?

There is no output schema, so the description carries the full burden of describing the return shape, and it does so field-by-field, including the conditional access payload. An agent knows what it will receive and under what runtime conditions.

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?

One parameter with 100% schema coverage (UUID pattern and provenance already documented in the schema). The description adds meaning by naming the upstream tools that produce the id, which is useful routing context but not syntax beyond the schema.

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 ('Get one AmpleRun rental by rental_id') and immediately enumerates the returned fields (state, cumulative charge, rate, funded-through time). It is clearly distinguishable from list_rentals, which it names as the source of ids.

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 tells the agent where to get the required rental_id ('list_rentals finds rental ids') and when access fields are available (while RUNNING, or read-only for a limited window after STOPPED). It lacks explicit exclusions or a statement of what to use instead when no access is needed, so it falls short of a full when/when-not treatment.

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