start_backtest

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

Annotations are all negative flags, so the description carries the behavioral burden. It usefully discloses asynchronous execution, immediate return with a run_id, persistence to .mt5tmp/runs/<run_id>.json, and the concurrency constraint. It does not detail terminal cleanup or lifecycle beyond what the timeout_sec parameter already conveys, but the key behavior is transparent.

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 sentences with no wasted words. The first sentence front-loads the core purpose, and the following sentences each add essential operational detail: polling, result fields, persistence, and concurrency. 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?

For a background-launch tool with 100% schema coverage and an output schema, the description is complete. It tells the agent what happens immediately, how to retrieve the result, where artifacts land, and the concurrency limitation that can affect invocation.

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%, and the description adds no parameter-specific meaning beyond the schema. The baseline of 3 applies because the schema already documents config, portable, and timeout_sec adequately.

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 clearly states a specific verb and resource: 'Launch a backtest in the background and return immediately with a run_id.' This distinguishes it from synchronous alternatives like run_backtest and clarifies what the tool produces. The follow-up reference to get_backtest further reinforces its role in the workflow.

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 gives clear operational guidance: poll get_backtest until status changes, read the final report_path and journal_notes, and be aware that only one terminal per install can test at a time. It does not explicitly contrast with sibling tools such as run_backtest, but the background-async context makes the intended use evident.

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