Run replayable command (ToolAhead)

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

Beyond the idempotentHint annotation, the description discloses that ToolAhead may replay a prefetched result and that toolahead.toml commands get their services started and health-checked instead of being replayed. It does not contradict the annotations; a small gap remains around return output/error behavior, but the key behavioral traits are covered.

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 short sentences, front-loaded with the primary purpose, followed by the replay nuance and an explicit fallback. No filler words; every clause contributes.

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 tool with no output schema and a moderate annotation set, the description covers main use cases, replay behavior, and alternatives. It does not describe the return format or failure modes, but for a command runner the core behavior is sufficiently specified.

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?

The schema already covers both parameters, so baseline is 3. The description adds meaning by explaining that the command must be exact/deterministic and by expanding accepted commands to include those declared in toolahead.toml, which is not captured in the schema's command description. It doesn't fully specify how toolahead.toml commands are formatted, but enough is added.

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 opens with a specific verb and resource: 'Run an exact deterministic test, build, or lint command that is listed in .prefetch-replay.json.' It clearly distinguishes this from sibling file tools by limiting to replayable commands and directing other commands to the native shell.

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?

It gives explicit when-to-use guidance: commands in .prefetch-replay.json or [commands] in toolahead.toml; it also states when not to use it: 'Use the agent's native shell for commands that are neither.' This is a clear exclusion rule.

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