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

Annotations already declare readOnlyHint true, openWorldHint true, idempotentHint true, and destructiveHint false, which align with the description. The description adds no extra behavioral context such as data source, rate limits, or handling of unsupported coins. Since annotations cover the safety profile, a baseline of 3 is appropriate.

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: the first states the core function, the second provides usage context and examples. Every sentence earns its place, with no unnecessary detail.

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 simple, single-parameter, read-only price lookup tool with strong annotations, the description covers purpose, usage, and supported coins. It does not discuss behavior for unsupported coins or return format, but these are minor gaps given the tool's simplicity and the presence of annotations.

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 provides 100% coverage for coinId, listing all accepted aliases in its description. The tool description repeats some of these examples but does not add meaningful new semantics beyond the schema, so it remains at the baseline for high schema coverage.

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 gets the current USD price of major cryptocurrencies and lists specific supported coins (BTC, ETH, SOL, BNB, HBAR). It positions itself as the PRIMARY tool for price questions, which helps differentiate it from other price-related tools in the sibling list.

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 when to use the tool ('Use this when the user asks about the price, value, or worth of...') and provides example queries. It does not explicitly state when not to use it or name alternative tools, but the primary guidance is clear and actionable.

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