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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description still earns credit by disclosing non-obvious behavioral facts the annotations cannot: prices are denominated in SOL per token, volume in SOL, and results are ordered oldest first. It stops short of saying what happens when no candles exist or how the window interacts with `limit`.

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 with zero filler; units and ordering are front-loaded where an agent will read them. Nothing repeats the title.

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 does a decent job of implying the return shape via 'OHLC' and the SOL units, plus ordering. But it leaves `interval` entirely unexplained, and gives no guidance on empty results or on what a 'candle' boundary means, which matters for a time-series endpoint.

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?

The description adds no parameter meaning at all — it never mentions `interval`, which is the one parameter lacking a schema description. It also does not clarify the interplay between the schema's 'most recent candles' and the stated 'oldest first' ordering. With 67% coverage, the undocumented parameter needed compensating detail that is absent.

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 and resource ('Price candles ... for a coin') and immediately disambiguates the content from raw trade tools by naming the shape (OHLC) and denomination (SOL per token, volume in SOL). It is clearly not get_coin_trades or get_trade_tape, though it does not name those siblings explicitly.

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?

Usage is implied — charting, price history, or per-coin analysis — but there is no explicit 'use this instead of X when Y' guidance, and no mention of prerequisites such as the coin existing or having candle data. The agent must infer the golden path from the sibling list.

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