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

Annotations already indicate read-only, non-destructive behavior, and the description adds useful context about content: it offers a rubric of honesty and clarifies what checks can and cannot prove. It also positions the tool as a prerequisite for interpreting backtests, supplementing the annotation profile without contradicting it.

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 tight sentences front-load the purpose, summarize the scope, and end with an actionable directive. There is no filler or redundant restatement of the tool name.

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 read-only explanatory tool with a single optional enum parameter, the description plus the schema gives an agent everything needed to call it correctly: what it covers, why to use it, and valid topic choices. No output schema is needed because the description communicates that this is reference material rather than a data-producing operation.

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 0%, so the description carries some burden for explaining the `topic` parameter, but it does not mention the parameter by name or explain its enum values. It does name several topic areas such as settlement, margin, and slippage, which partially overlap with enum values, providing some guidance but not complete compensation.

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 frames the tool as an educational methodology reference, specifying the resource ('how a result is produced and how to judge it') and concrete topics such as entry pricing, settlement, margin, slippage, and the honesty rubric. It also distinguishes itself from siblings, none of which explain methodology.

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 final sentence gives an explicit trigger: 'Read this before trusting any backtest, including ours.' This tells an agent when to call the tool, though it does not enumerate exclusions or name a specific alternative tool.

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