replay_start

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

No annotations are supplied, so the description carries the full burden and does well: it declares STATE_MUTATING, explains the concrete effect ('Switches chart into Replay mode, rewinds visible price action'), and states a prerequisite ('Requires market symbol with historical data at chosen date'). It omits behavior when replay is already active or on invalid dates, but the mutation semantics are unusually well disclosed.

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 purpose followed by labeled WHEN TO USE / SIDE EFFECTS / LIMITATIONS sections; every clause is informative. The labeled format is slightly mechanical but not wasteful.

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 state-mutating tool with no annotations and no output schema, the description covers purpose, trigger context, side effects, and preconditions, which is most of what an agent needs. Gaps remain around state when replay is already running and what (if anything) is returned.

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 'date' parameter, so the schema already documents format (YYYY-MM-DD) and the omit-behavior. The description only restates the same omit-behavior, adding no syntactic or semantic detail beyond the schema. Baseline 3 is appropriate.

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 ('Enter TradingView Bar Replay mode') with scope ('at a specified historical date or first available bar'). It is clearly distinguishable from siblings like replay_step, replay_stop, and replay_status without opening any schema.

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 WHEN TO USE clause gives clear context ('initiating historical simulated forward-testing or practicing trade executions bar by bar'), which is a real scenario. It stops short of naming alternatives or exclusions, e.g. that replay_step/replay_autoplay should be used after entry rather than re-calling this tool.

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