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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description goes further by explaining the selection behavior (out-of-sample and walk-forward validation), the ranking behavior (by worst walk-forward fold, consistency over size), and explicitly notes 'without re-running anything,' which confirms no side effects and adds meaningful behavioral context.

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 sentences, no fluff. The core selection criterion is front-loaded, the ranking philosophy is stated clearly, and the read-only benefit is added at the end. 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?

With an output schema, clear annotations, and documented parameters, the description covers the essential purpose, selection criteria, ranking, and read-only nature. Nothing an agent needs to decide whether to call this tool is missing.

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 50% (order has a description, limit does not). The tool description adds semantic value by clarifying what the default consistency ranking means ('Ranked by worst walk-forward fold — consistency, not size'), which enriches the order parameter. The limit parameter is self-evident from its type and bounds, so the description does not need to elaborate.

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 resource ('strategies from THIS account's history') and a specific filtering criterion ('held up under out-of-sample and walk-forward checks'), and contrasts with 'not merely ones that made money.' This distinguishes it from sibling tools like list_backtests and run_backtest without ambiguity.

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 strong context: it answers what has worked without re-running anything, implying when to use it (when you want validated historical strategies) and when not (when you need a fresh backtest or pure P&L ranking). It does not explicitly name alternative tools, so it stops short of a full 5, but the guidance is clear.

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