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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful context that annotations cannot convey: the dual access model (x402 micropayment vs API key) and the per-call cost. However it says nothing about what an evaluation returns or how signal_name is resolved.

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 segments with the core action front-loaded and access/payment details relegated to a bracketed note. Slight waste in the redundant phrase 'and parameters', but overall efficient.

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 no output schema, undefined nested MarketDataBar shape, and opaque 'parameters' object, the description should have explained expected evaluation output and bar structure. It instead spends its detail budget on payment mechanics, leaving the agent unable to construct a valid call confidently.

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 only 33% and the most important parameter, market_data, references a MarketDataBar definition with an empty properties object, so its shape is entirely undocumented. The description's phrase 'market data and parameters' adds no meaning beyond the schema, and 'parameters' remains an opaque free-form object.

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 ('evaluate') and resource ('a signal') plus the required inputs, which is enough to distinguish it from listing/creating siblings. It does not explicitly distinguish itself from evaluate_multiple_signals_series or evaluate_strategy, which is the main gap.

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?

No when-to-use guidance, no prerequisites, and no mention of when to prefer the multi-signal or strategy-evaluation siblings. The agent is left to infer selection from the name alone.

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