crypto_prices

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

With no annotations, the description carries the full burden and does well: it discloses the data source (DefiLlama), the cost ($0.002 USDC per call), and p99 latency (500ms), which are exactly the operational traits an agent needs before invoking. It omits failure behavior and whether a payment/auth precondition is required to spend USDC.

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?

Front-loaded summary followed by a numbered mode list and a compact params/cost/latency line; nearly every clause carries information. It is dense and slightly repetitive ('Crypto Price Lookup — Crypto price and token price lookup') but not wasteful.

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?

No output schema or annotations exist, so the description must stand alone; it covers input modes, accepted identifier formats, target currencies, source, cost, and latency. The main omissions are response shape and error/empty-result behavior, plus the unresolved 50-vs-25 limit conflict.

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 already 100%, so the schema documents all four parameters with examples and defaults; the description correctly recaps currencies default and the chain:address format. However it states 'up to 50' coins while the schema caps at 'Max 25 coins per call', a direct numeric conflict that could cause an agent to build an over-limit request, so no credit above the schema-driven baseline.

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?

Names a specific verb and resource ('crypto price and token price lookup', live spot price and 24h change) and enumerates the three input modes (coins, tokens, historical via `at`) with concrete examples. An agent can distinguish this from siblings like exchange_rates, crypto_news, or defi_tvl without opening any schema.

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 three modes are clearly stated with the condition that selects each (coingecko IDs/tickers for coins, chain:address for any DEX-traded token, `at` for historical USD prices), which is strong routing guidance. It stops short of naming when NOT to use it (e.g. fx-rate conversion vs exchange_rates, or token safety vs token_security/token_verdict).

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