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

The description adds valuable behavioral context beyond the readOnlyHint and destructiveHint annotations: it discloses HTTP 503 responses with no charge when upstream sources are unavailable, an SLA of $0.10 USDC per call, and a data_source field for provenance. The repeated 503 sentence and irrelevant FRED provenance mention detract slightly, but the disclosure is substantial.

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 front-loads the core purpose but becomes repetitive, with two identical statements about HTTP 503 behavior and an out-of-place reference to 'fred_api/fred_csv/fred_mixed' that is irrelevant to crypto. These redundancies and inconsistencies make it longer than necessary without adding value.

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 description covers the output components (Pearson pairs, beta, dominance, diversification signal), source, error behavior, and cost, which is good for a tool without an output schema. However, it fails to explain the only parameter (period), and the duplicate 503 text plus FRED provenance error leave gaps in the tool's operational semantics.

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 input schema has one optional parameter 'period' with an enum of 7d/30d/90d, yet the description never explains this parameter. It mentions '30-day rolling' as a fixed attribute, which conflicts with the parameter's ability to vary the window. With 0% schema description coverage, the description should compensate but does not.

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's function with a specific verb and resource: it computes a 30-day rolling correlation matrix for BTC, ETH, and SOL, including Pearson pairs, beta, dominance, and diversification signals. This distinguishes it from sibling benchmark tools, which focus on different asset classes or metrics.

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 implicitly targets 'crypto portfolio agents' and mentions a live source, giving some usage context. However, it does not explicitly state when to use this tool versus alternatives or provide exclusions, so guidance is implied rather than explicit.

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