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

Annotations already cover read-only/idempotent/non-destructive, and the description adds material behavior beyond them: tick-source (DefiLlama aggregated oracle with confidence score), symbol resolution against top 1,000 market-cap coins, ambiguity handling that lists alternatives, and an isError contract for invalid input or upstream failure. That is exactly the extra context annotations cannot express.

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?

Dense and front-loaded: identification, resolution behavior, when-to-use, cost, then errors. It runs long and repeats the 'any chain' framing, but almost every clause carries routing or behavioral information rather than filler.

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 an output schema present, return-format explanation is unnecessary, and the description still covers resolution, ambiguity, limits, cost, error semantics, and the cross-server alternative. Nothing an agent needs to invoke the tool correctly is missing.

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 100% (baseline 3), and the description usefully adds accepted asset forms not obvious from the schema: bare symbol, 'coingecko:ethereum', 'base:0x…', bare 0x address with chain, and Solana mint. It could have clarified how chain interacts with a bare 0x address beyond the passing mention.

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 (live USD price and 24h change for crypto assets) with scope ('up to 30', 'any chain') and distinguishes itself from the nearest sibling by naming price_history for history and price on another server for Solana mints. An agent can route correctly without opening a 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?

Explicit 'When to use' block, an explicit alternative for Solana-mint lookups, and an explicit alternative for historical data. Also states cost ('free') and that failed calls are not charged, which is decision-relevant context.

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