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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds only a data-freshness boundary (hourly USD prices for the last 7 days) and the notion of an 'outside reference' benchmark; it says nothing about behavior for an unknown symbol, units/currency of prices, timezone, or whether missing venues mean zero or no data.

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?

One dense sentence, front-loaded with the resource and then the payload breakdown; there is no filler and each item listed corresponds to real output. It reads as a sentence fragment ('One token: ...') without a verb, which is slightly awkward 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?

With no output schema, the description carries the return-value burden, and it does so reasonably by enumerating each field group an agent would receive. Gaps remain around error behavior for unknown symbols and the definition of terms like 'premium to its outside reference', but for a single-parameter read tool the core is covered.

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% and the single symbol parameter is documented well in the schema, including format examples and how to enumerate symbols. The description adds no additional meaning about the symbol argument, so baseline 3 applies.

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?

The description names the resource (one token) and enumerates exactly what data comes back: price, changes, liquidity/volume, per-venue price, premium to an outside reference, pools with fee APR, and 7-day hourly USD prices. That is specific enough to distinguish it from list_tokens or pools without opening a schema, though it never states a verb or explicitly contrasts itself with a sibling.

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?

There is no when-to-use or when-not guidance, and no mention of alternatives such as list_tokens for discovering symbols or pools/venues for narrower views. The only routing hint (list_tokens() gives every symbol) lives in the input schema rather than the description, so the description itself gives an agent no decision criteria.

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