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

Annotations only declare the read-only/idempotent safety profile; the description adds substantial context beyond that: keys must run on the caller's Dev/Pro/Enterprise key via Authorization header, no key yields DP401_API_KEY_REQUIRED without sending anything upstream, a free key yields 403, and Dev-plan history caps at 30 days. It also discloses the aggregation semantics (volume-weighted price, summed volume).

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 with the core purpose and aggregation caveat before alternatives, then auth behavior, then params. It is dense and long, but nearly every sentence carries operational weight; only the param enumeration slightly duplicates the schema rather than adding new information.

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?

An output schema exists, so return-value explanation is unnecessary, and the description still conveys the shape (a time-series array). It covers auth requirements, error paths, plan limits, aggregation semantics, and sibling routing, leaving no gap an agent needs to call it correctly.

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%, so most parameter detail is already documented. The description still adds value by foregrounding the relative-offset convention as the 'easiest' form and by noting 'there is no inversed parameter on this endpoint', a disambiguation not in the schema, though it largely restates the interval/limit/default facts.

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 (get historical USD OHLCV candles for one token) and immediately qualifies the scope: aggregated across every pool the token trades in, volume-weighted, not a single pair. It explicitly distinguishes itself from getPoolOHLCV and getTokenDetails, so an agent can route without opening either 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?

Gives explicit use cases ('price history of this token', 'USD chart for this token'), names two alternatives with the condition that selects each (getPoolOHLCV for a single pair, getTokenDetails for current price), and even describes the fallback path when auth fails. Nothing is left to inference.

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