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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond annotations: the cost (0.2 points per call). It says nothing about pagination behavior or result size limits, which the 'before' and 'limit' params imply matter.

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 short sentences with zero filler, resource stated first and the cost note isolated in parentheses. Nothing is padded or repeated from 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?

For a 4-parameter market-data tool with no output schema and 75% schema coverage, the description is minimally adequate: it identifies the resource and the cost but omits timeframe semantics, pagination via 'before', and any sense of the returned candle shape. An agent could call it, but without full confidence about pagination or timeframe defaults.

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 description coverage is 75%, with limit, before, and symbol documented in the schema itself; timeframe is an enum but has no description anywhere. The description's 'coin or pair' phrasing loosely reinforces the symbol parameter but adds no syntax or format detail beyond the schema, so the 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?

States the specific resource (OHLCV candles) and the input domain (coin or pair), which clearly separates it from get_crypto_quotes and get_crypto_indicators. The verb is only implied by the name rather than spelled out, and no sibling is named explicitly, so it falls just short of a 5.

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 guidance on when to choose this over get_crypto_quotes, get_crypto_indicators, or market_status, and no mention of timeframes or use cases. The agent must infer usage entirely from the name and schema.

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