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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds concrete behavioral detail by specifying the returned fields and the low-latency, snapshot-style nature of the lookup. It does not describe rate limits or signal methodology, but those are not critical for safe invocation.

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 concise sentences earn their place: the first front-loads the exact outputs, and the second adds the latency/use-case profile and allowed assets. No filler or redundant explanation beyond a useful quick reference list.

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 one-parameter read-only lookup, the description covers the output shape, asset scope, and intended use. The main gaps are the unspecified quote currency and the criteria behind the bullish/bearish/neutral signal, but these are minor for a snapshot tool.

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 schema covers the single parameter completely with an enum and description. The description merely repeats the allowed asset list without adding extra meaning such as price quote currency or formatting, so it does not improve on the schema.

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 specifies the tool's output: current price, 24h and 7d percentage change, and a bullish/bearish/neutral signal. It also defines the resource scope as a major crypto asset from an explicit allowed list, which distinguishes it from simpler price-only or sentiment-focused sibling 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 gives clear intended usage contexts: low-latency lookups for dashboards, bots, and alerts. It does not explicitly name alternatives or state when not to use this tool, but the context is strong enough for an agent to infer appropriate selection.

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