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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is fully covered without the description. The description's only added value is naming the fields returned, which matters since there is no output schema, but it says nothing about snapshot freshness, units, or currency.

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?

A single, front-loaded fragment with zero filler. It is appropriately sized for a no-argument read, though the missing verb makes it read as a field list rather than a statement of capability.

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 output schema, the field enumeration does useful work in telling the agent what comes back. However, for a tool sitting next to get_market_data, the absence of any scoping or differentiation leaves a real selection gap that the description should close.

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 takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; no parameter information is required or missing.

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 enumerates the metrics returned (market cap, 24h volume, BTC dominance, active assets/markets) but never states a verb or explicitly says it returns a snapshot of the global crypto market. It also gives no signal to distinguish it from the sibling get_market_data, so the agent must infer the difference from the name alone.

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 when-to-use guidance, no mention of alternatives, and no exclusions. The overlap with get_market_data and get_risk_signals is left entirely unresolved, which is the main selection risk for this tool.

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