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

readOnlyHint=true already establishes the safety profile, so the description's main addition is the data source (CoinGecko) and that values are live. It does not disclose refresh cadence, caching, rate limits, or behavior when the upstream API is unavailable. Useful context beyond annotations, but not rich.

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 sentence that names the source and then lists the payload fields. No filler, no repetition of the title.

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 description correctly takes on the job of enumerating returned fields, which is the key completeness requirement here. It omits only secondary details such as refresh interval or failure behavior, which are minor for a no-arg read 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?

There are zero parameters, so per the rubric the baseline is 4. The schema description coverage is 100% and there is nothing for the description to compensate for.

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?

States a specific verb and resource (get XRD market data) and enumerates exactly what is retrieved: USD/EUR price, 24h change, market cap, circulating supply, TVL. This is unmistakably distinct from every sibling, which are all Radix node/network/manifest tools rather than market-data lookups.

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 never says when to reach for this tool, when not to, or what alternatives exist. For a zero-parameter convenience tool this is a mild gap, but no usage context is provided at all.

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