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

With no annotations, the description carries the full behavioral burden, and it does disclose the access model: 0.02 USDC via x402 PAYMENT-SIGNATURE header or an API key with no per-call charge. That is genuinely valuable and beyond structured fields. It says nothing about what the evaluation computes, error conditions, or whether the operation is read-only.

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 core purpose is front-loaded in a single sentence, and the access note is set off in brackets. Both parts earn their place, though the payment explanation is verbose relative to the single-sentence purpose.

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 3-parameter tool with a nested, essentially empty MarketDataBar definition, no output schema, and no annotations, the description is too thin. An agent still cannot tell what a bar in market_data must contain or what an 'evaluation' returns.

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 33%: signal_name is trivially labeled, while market_data is an array of an empty MarketDataBar definition and parameters is an undescribed object. The description adds no meaning to any of the three parameters, so the opaque market_data shape is left entirely unexplained.

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+resource ('Evaluate a signal') with the inputs it consumes, so the agent knows it is an evaluation call rather than a data fetch. It does not distinguish itself from close siblings such as evaluate_multiple_signals_series, evaluate_strategy, or validate_signal_params, so 4 rather than 5.

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 offers no when-to-use or when-not-to-use guidance and never names an alternative. The bracketed text is about how to pay, not about which evaluation tool to pick.

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