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

Discloses rich behavior beyond the annotations: it is throwaway and deleted on close_sandbox or expiry, limited to one-at-a-time per caller, returns addresses plus expiry and limits, and warns that the addresses are credentials anyone could use ('keep them to yourself'). It also explains the capacity-fallback behavior ('says when the next one is free').

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?

Purpose and the no-account/no-key constraints are front-loaded, followed by duration, return contents, security warning, and capacity limits. Every sentence carries a distinct fact, though the ornate metaphor slightly inflates the wording.

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?

Given an output schema exists, the description need not detail return values, yet it still summarizes them (addresses, end time, limits). Combined with the deletion, capacity, and credential-handling notes, an agent has everything needed to call it correctly.

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?

Zero parameters, so the baseline is 4. The description usefully notes the invocation returns addresses, an end time, and limits, adding a bit of meaning even though there are no parameters to disambiguate.

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 and resource: it opens a throwaway sandbox house for a few hours, on core.blue's server, with no account/key/person. This distinguishes it from request_house (formal request) and close_sandbox (deletion). The heavy metaphor ('house', 'kernel of Atlantis') adds flavor but slightly obscures rather than clarifies.

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?

Explicitly frames when to use it: 'try a house yourself before anyone decides,' implying it precedes the formal request_house flow. It also names close_sandbox as the termination alternative. It does not explicitly exclude or contrast request_house by name, so it falls short of a full when/when-not/alternatives statement.

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