blockrun_modal

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

Description adds critical behavioral context beyond annotations: billing model (timeout is billed lifetime, no refunds), pricing tables for different time ranges and GPUs, and common endpoint patterns. No contradiction with annotations (destructiveHint=true is supported by running untrusted code).

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?

Well-structured with bullet points and sections, front-loaded purpose. Every sentence adds value. However, it is somewhat lengthy; could be slightly more concise without losing key details.

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 the complexity (pricing, multiple endpoints, destructive nature), the description is highly complete. It covers purpose, usage, billing, and endpoints. References external 'modal skill' for full tables, which is acceptable. No output schema needed as description explains return implications (prices, sandbox_id).

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%, but description adds significant value: lists common paths (sandbox/create, exec, etc.) with example request bodies, and clarifies pricing implications for timeout and GPU parameters. This goes beyond the schema's property 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 'Run isolated code in a BlockRun-hosted Modal sandbox' — a specific verb (run) and resource (Modal sandbox). It distinguishes from sibling tools (e.g., markets, wallet) by focusing on ephemeral code execution with GPU options.

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 says when to use: 'when you need: a clean ephemeral environment, GPU access... or a safer place for untrusted code.' And when not to: 'Prefer local tools for normal repo work.' This provides clear alternatives.

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