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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds genuinely useful behavioral context: oldest-first ordering, inclusion of base volume, a per-call cost of $0.001 USDC, and byte-identical equivalence to a specific REST endpoint. This greatly exceeds the structured metadata.

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?

Two sentences carry all the essential information without repetition. The core scope and ordering are front-loaded, and the cost and byte-identical endpoint note are high-value additions with no wasted words.

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-value details are already covered. The description adds selection scope, ordering, volume semantics, cost, and endpoint equivalence. It is only mildly incomplete because accepted timeframe values are not explicitly listed, leaving that detail to external v2 API knowledge.

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 the baseline applies. The description's query example reinforces how pair, timeframe, and limit combine, but it does not add new parameter meaning beyond the schema. The main gap is that accepted timeframe values are not enumerated; the description only points to the v2 API.

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 identifies the resource precisely: Bitfinex spot pair OHLC candles at v2 API timeframes, ordered oldest first, with base volume per bucket. The venue and endpoint name clearly distinguish it from sibling candle tools for other exchanges, and the title reinforces the resource type.

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 description makes the use case explicit — Bitfinex spot pair candles — which is sufficient to route an agent to this tool over other venue-specific candle tools. It does not explicitly name alternatives or state when not to use it, so it stops short of a 5.

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