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 real work: it discloses that cells execute against a live editor via a privileged `eh` API (i.e. side effects are possible), states the out-of-band prerequisite, reports current unavailability, and points at remediation tools. Still missing: failure behavior, whether/timeout effects, and what a run yields (logs, return value).

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-loaded with the core action in the first clause, and the parenthetical groups the prerequisite and sibling routing efficiently. Minor waste: the 'kernel is not available right now' status claim duplicates runtime information that belongs in a status check and may be stale inside a static description.

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 an execute-arbitrary-code tool with no output schema and no annotations, the definition covers prerequisites and alternatives but never explains what a successful run produces (return value, output channel, how cell results surface). That gap matters for an agent deciding between `code` and `path` and interpreting results.

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 description coverage is 100% and the schema already states the mutually exclusive `code`/`path` rule, timeout semantics, and optional save name. The description adds no parameter-level meaning beyond the schema, so the baseline 3 applies.

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: runs a JavaScript cell in the Effect House `eh` kernel driving the open editor. The generic name `run` is disambiguated by the body, and it names sibling tools (`instances`, `launch`) that cover adjacent concerns, though it does not contrast against `reset` or `status`.

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?

Gives clear routing: if the kernel is unavailable, call `instances`; to open the editor, call `launch`. Prerequisite (Effect House must be open) is stated explicitly. It lacks an explicit 'prefer X over run when...' rule or guidance on choosing `code` vs `path` beyond the schema.

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