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

The description adds behavioral details beyond annotations: cache miss latency (up to a minute), rate limiting, and the nature of a 'public what-if engine'. It does not contradict annotations (readOnlyHint=false is consistent with a non-destructive execution that may produce results). However, it does not fully detail side effects or authentication needs.

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 a single well-structured sentence with a parenthetical for additional context. It is front-loaded with the main action and includes essential behavioral notes (cache, rate limit) and return value summary. No unnecessary words.

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?

Given no output schema, the description fully enumerates the return fields (net return, max drawdown, trade count, robustness score, overfitting verdict, shareable URL). It also covers latency, rate limits, and the fixed trading pair. The tool's complexity is well-addressed for an agent to invoke correctly.

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?

With 100% schema coverage, baseline is 3. The description adds value by specifying that the strategy comes from list_strategies, that the trading pair is BTC/USDT, and that the backtest is a 'real' execution on a public engine. These details augment the schema descriptions without redundancy.

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 the verb 'Run a real backtest', specifies the resource 'strategy template on BTC/USDT', and includes the action scope (start date). It distinguishes itself from siblings like check_overfitting or compare_strategies by being the dedicated backtesting tool.

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 implicit usage context (expected latency, rate limits) but does not explicitly state when to use this tool versus alternatives. There is no exclusion guidance or direct mention of sibling tools, requiring the agent to infer usage.

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