Crypto correlation matrix

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

Annotations already provide readOnlyHint and openWorldHint, covering the safety profile. The description adds substantive behavioral detail: Pearson correlation, 30-day rolling window, daily returns, and top perpetuals as the universe. This meaningfully explains what computation the tool performs beyond the annotations.

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, each earning its place: the first gives trigger scenarios and the second describes the output. No fluff, and the use cases are front-loaded.

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 parameters and no output schema, the description explains the return value well, including method, window, and data universe. It could be slightly more specific about what 'top perpetuals' means or how an agent extracts a pair-specific answer from the matrix, but for a zero-param tool this is largely complete.

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 tool has zero parameters, so schema description coverage is trivially 100% and there is no param info to add. The description appropriately omits param details, and the baseline for zero-param tools 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?

The description names a specific verb and resource: 'Returns the 30-day rolling Pearson correlation matrix of daily returns across the top perpetuals.' It also lists concrete user intents (two-coin correlation, decorrelated pairs, alts tracking BTC), making it clearly distinguishable from the sibling analytics tools.

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 explicitly says 'Call this when the user asks' and gives three representative queries, which tells the agent when the tool is appropriate. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for selection among the large sibling list.

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