cancel_backtest

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

Annotations already flag the operation as destructive (destructiveHint=true), and the description adds specifically what gets destroyed—the terminal of a running background backtest—and the subsequent outcome that no report is produced. This goes beyond the bare annotation and gives the agent an important behavioral consequence.

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?

Two short sentences with no filler. The action and object are front-loaded, and the second sentence delivers only the critical consequence. Every word 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 simple one-parameter destructive tool with a full input schema and an output schema, the description covers the core action and the important outcome of a cancelled run. A minor gap is the absence of any statement about the behavior if the backtest is not actually running, but this is not a blocker for correct 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?

The run_id parameter is fully described in the schema, including its provenance as the identifier returned by start_backtest/run_backtest. Since schema description coverage is 100%, the description does not need to add parameter details, and the baseline score of 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?

The description opens with a specific action ('Kill the terminal') and a precise target ('a running background backtest'), then adds the key consequence that no report is produced. This clearly distinguishes the tool from reading, listing, and starting backtests, even without naming a sibling.

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 the intended use case: a background backtest that is currently running and needs to be terminated. However, it does not explicitly contrast itself with the related sibling kill_terminal or explain when to choose this over that tool, leaving the routing partially to the agent's inference.

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