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

No annotations are provided, so the description must carry behavioral disclosure; it does disclose the comparison scope and metric set. However, it says nothing about output format, data source/freshness, or behavior on invalid coin identifiers, leaving a gap for a first-time agent.

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?

One concise, front-loaded sentence. Every word contributes: action, range, resource, and comparison dimensions. No filler or schema repetition.

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 two-parameter read-only comparison tool, the description covers the main action and metrics, but with no annotations and no output schema it leaves unspecified the return shape and how vs_currency affects the comparison. An agent could probably call it correctly, but not with full confidence about the response.

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 description adds a useful constraint (2–5 coins) beyond the schema's 'Array or comma-separated list' example, but it does not explain the vs_currency parameter, whose schema description is missing. Because schema coverage is only 50%, the description should have provided at least some semantic contribution for the un-described parameter.

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?

Clearly states a specific action ('Compare') and resource ('cryptocurrencies'), with precise comparison metrics (price, mcap, volume, 24h change) and a 2–5 count constraint. This distinguishes it from siblings like get_price or top_coins without needing schema details.

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 phrase 'Compare 2–5 cryptocurrencies side by side' implies the intended use case of multi-asset comparison, but the description never explicitly states when to use it instead of convert, get_price, or top_coins, nor any exclusions.

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