scratchrun_exec

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

With no annotations provided, the description carries full burden and excels: it discloses hard-purge/no persistence, full internet egress with RFC 1918/cloud metadata blocks, and how to retrieve artifacts. This is rich behavioral context beyond basic function.

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 description is compact and front-loaded with the primary purpose. Every sentence adds value—covering security, persistence, file capture, and secrets—without redundancy or filler.

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?

Despite no output schema or annotations, the description provides comprehensive context: execution environment, security boundaries, state persistence, artifact retrieval, and secrets handling. It addresses the tool's complexity and likely pitfalls.

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%, providing baseline 3. The description adds extra meaning by explaining the purpose of return_files (base64-encoded artifacts) and recommending env for secrets, reinforcing and supplementing schema descriptions.

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 clearly states the tool executes code in an ephemeral, MicroVM-isolated sandbox, using a specific verb and resource. It conveys the core function and distinctive characteristics (isolation, ephemerality) without ambiguity.

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?

Provides practical usage guidance such as using return_files to capture output artifacts and passing secrets via env instead of code strings. It implies appropriate contexts (e.g., untrusted code, one-off executions) though it doesn't explicitly contrast with alternatives, as none are listed.

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