replay_trade

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, so the safety profile is known; the description still adds two things the annotations cannot express — that no broker order API is called and that the result verifies simulated position direction. It stops short of saying the replay must be active or what happens on a position-direction mismatch.

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?

A single front-loaded sentence with no filler; the simulation guarantee is stated early. It is slightly under-sized for a three-required-parameter mutation tool, but nothing in it is wasted.

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?

With no output schema and three required parameters, the description should cover the replay-active prerequisite and what the position-direction verification yields. Those gaps are partly filled by the schema's parameter descriptions, leaving it adequate but not complete.

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 coverage is 67%: target_id and expected_layout_id are documented in the schema, including the mismatch-aborts behavior, and action's enum is self-explanatory. The description adds nothing about the enum values or the layout-ID guard, so with partial coverage a baseline 3 is right.

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?

Specific verb (place) plus resource (simulated Bar Replay buy/sell/close action) and an explicit negative scope ('never calls a broker order API') that separates it from real trading. It does not name the nearest sibling (paper_trade) or the replay_* family it belongs to, so an agent must infer the boundary itself.

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 phrase 'Bar Replay' implies usage during an active replay session, but the description never states the prerequisite (replay_start must be running) or when to prefer paper_trade instead. Usage is suggested rather than specified.

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