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

With no annotations, the description carries the full burden and discharges it well: 500-char input limit with the exact error, data window (up to 40 items over 7 days), ranking logic, free-vs-paid gating, and the degraded path where synthesis is unavailable (answer null, relevant headlines, no charge). The as_of/timestamp behavior is also disclosed.

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?

Purpose is front-loaded and the per-parameter and behavioral details are separated logically; nearly every clause adds actionable information. It is dense and long, but not padded, so it earns most of its space.

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 and no annotations, the description still explains return fields (answer, relevant, as_of) and the failure mode, plus payment/auth requirements. An agent has everything needed to invoke and interpret the call.

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 must compensate, and it documents all four parameters: question length limit, lang's en/pl semantics with an en fallback, session_token's provenance, and payment's x402 role. This is materially more than the bare schema supplies.

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 (ask a market question in natural language) and a precise scope: the answer is written only from Tachyo's recap items. That framing distinguishes it from the structured-analysis siblings, which are all typed data retrievals rather than free-form QA.

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?

Gives clear conditions: free returns a connect-CTA, and a grounded answer requires session_token (from verify_wallet_ownership) OR an x402 payment proof, naming the sibling that produces the token. It also states an exclusion (no wallet lookups, never covers positions or track record), but offers no explicit guidance on when to prefer this over the other market tools.

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