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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds genuinely new behavioral context: no cost, no market-data access, and concrete failure classes it detects (impossible thresholds, strategies with no exit). It does not describe the shape or granularity of the verdict returned.

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 short sentences, front-loaded with the core action, then cost/safety, then concrete examples of what it catches. No filler.

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, read-only tool with no output schema, the description covers purpose, cost profile, and detection scope, and annotations carry the safety profile. The only real gap is that the return value/verdict format is not described.

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% for the single 'spec' parameter, which points the agent at get_strategy_spec_rules. The description adds no further meaning about the spec object's expected structure, so the baseline of 3 applies.

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?

States a specific verb (validate) and resource (a strategy spec) plus the exact scope of the check: proving whether rules can ever fire. The phrase 'without running it' and 'touches no market data' implicitly separates it from run_backtest, the main alternative an agent might confuse it with.

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 context for use ('costs nothing', static analysis) that signals this is a cheap pre-flight check before incurring backtest cost, but it never explicitly names run_backtest as the alternative or states when this tool should be skipped.

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