replay_start

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

With no annotations, the description carries the full burden. It states the primary behavior (starting replay mode) and mentions the optional date, but does not disclose side effects, state changes, or requirements like having a chart open. This is acceptable for a simple mode-toggle tool but lacks depth.

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 a single sentence of nine words, front-loaded with the action verb 'Start' and the resource. Every word earns its place, with no redundant 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?

For a tool with one optional parameter and no output schema, the description is mostly complete. It covers the primary function and the optional parameter. It does not place the tool within the replay workflow (e.g., suggesting replay_step for advancing), but that is not essential for executing the tool correctly.

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% for the single optional 'date' parameter, which is fully documented. The description's mention of 'optionally at a specific date' merely reiterates the schema, adding no extra semantic value beyond the structured data.

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 uses a specific verb 'Start' with a clear resource 'bar replay mode', distinguishing it from siblings like replay_stop, replay_status, and replay_step. It unambiguously states the tool's function.

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?

The description implies usage context (entering replay mode) but does not explicitly contrast with siblings such as replay_autoplay, replay_step, or replay_trade, nor does it state prerequisites or follow-up actions. It provides only implied guidance.

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