start_chart_replay

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does reveal meaningful behavior: expected_symbol and expected_timeframe are checked immediately before the write, confirm=true is required, and Replay Trading orders/autoplay are never used. However, it leaves ambiguity around what 'Preview' means, whether an existing replay is replaced, and what side effects or return values occur after the write.

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 three concise sentences with no filler. The primary purpose is front-loaded, and the key constraints are stated clearly. Every sentence earns its place.

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?

The tool has no annotations and no output schema, so the description needs to cover more context. It covers the core action and critical guardrails, but it lacks guidance on follow-up tools, expected return behavior, and what happens to any existing replay session. It is adequate for a simple start action but still leaves clear gaps.

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 low at 25%, so the description must compensate. It adds semantic meaning for expected_symbol and expected_timeframe by saying they are checked immediately before the write, and it clarifies that confirm must be true. However, start_at is only implied by 'one historical instant' and is not explicitly linked to the parameter, and no additional parameter semantics are provided.

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 names a specific verb ('Preview or start'), a specific resource ('TradingView Bar Replay on the active chart'), and a precise scope ('at one historical instant'), distinguishing this from sibling tools like step_chart_replay, stop_chart_replay, and get_replay_status. It is not a tautology and immediately communicates what the tool does.

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 provides useful context: it is for entering replay at one historical instant, confirm=true is required, and Replay Trading orders/autoplay are never used. However, it does not explicitly state when to use this tool versus alternatives such as step_chart_replay, stop_chart_replay, or get_replay_status, or mention prerequisites like having an active chart.

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