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

The description adds that the data source is Coinbase Exchange and lists granularity options, but does not disclose additional behaviors such as time range limits or pagination. Annotations already declare readOnlyHint and idempotentHint, covering safety, and the description aligns with these without contradiction, offering minimal extra behavioral context.

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?

The description is two sentences long, front-loaded with the core action, and contains no filler or redundant words. Every clause contributes meaning, making it highly concise and well-structured.

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?

The tool is simple, but the description lacks an explanation of the start/end parameters and how to specify time ranges. It also uses human-readable granularities (1m) while examples use seconds (3600), which could confuse. The presence of an output schema offsets the need to describe return values, but the parameter gaps remain.

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?

With 0% schema description coverage, the description must explain parameters. It explains granularity via the list of intervals and calls the pair 'crypto pair' (product_id), but it does not describe the start and end parameters, which are essential for time range filtering. The schema examples show sample values but lack explicit semantics, leaving a gap.

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 clearly states the tool provides OHLC candles for a crypto pair on Coinbase Exchange, with a specific list of granularities. It distinguishes from sibling tools like product_ticker and product_book by explicitly focusing on candle data, making the purpose unmistakable.

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 phrase 'Use for charting and backtesting' provides clear context for when to use this tool. While it doesn't explicitly mention alternatives or exclusions, the context is sufficient given the sibling tool family and the specific use case stated.

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