run

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

With no annotations, the description carries the full burden and does disclose the critical trait: effects really happen unless `replay` names a recording, which is the key safety fact. It also explains the grant-narrowing model and that the response reports program output and exit. It stops short of error/failure behavior or any permission prerequisites beyond the grant.

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?

Three tight sentences that front-load what the tool does before the grant and effect caveats. The backticked jargon ('grant', 'narrowed', `replay`) is dense but every sentence carries information.

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 9-parameter execution tool with no annotations and no output schema, the description covers the essentials: it runs `main`, it returns printed output and termination status, and side effects are real unless replayed. Remaining gaps are failure modes and timing/resource limits, which are secondary here.

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%, so the baseline is 3. The description goes beyond the schema by framing `deny`/`allow_*`/`at_most` as narrowing the program's declared grant, and by clarifying that `replay` substitutes for every effect so nothing is written or sent — conceptual meaning the per-field descriptions do not tie together.

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: run a program's `main` on the VM and return what it printed and how it ended. It anchors to `renyi run`, but that is an external CLI reference rather than a sibling tool, so differentiation from `check`, `effects`, or `run_tests` is left implicit.

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?

There is no explicit when-to-use guidance or exclusion against neighbors like `check` or `run_tests`. The phrase 'Check a program and run its main' ambiguously reuses a sibling's name, so the agent must infer that this tool actually executes rather than statically checks.

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