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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered structurally. The description contributes nothing beyond that: no currency/unit for the returned figure, no data freshness or caching behavior, and no indication of behavior for unknown symbols.

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 front-loaded sentence with no filler and no repetition of annotation or schema content. Nothing in it is wasted.

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, fully annotated single-parameter read with no output schema, the description is essentially sufficient. The minor gap is that a market-cap figure's currency/unit and freshness are never stated, which an agent may need to interpret the result.

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 is a single parameter with 100% schema description coverage, including examples (BTC, ETH, SOL), so the schema does the work. The description only restates "by symbol" and adds no format or case-sensitivity detail beyond 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?

States a specific verb and resource ("Get the market capitalization") scoped to "a specific asset by symbol," which distinguishes it reasonably from list_market_caps. It does not explicitly name get_market_cap_history or list_market_caps as alternatives, so sibling differentiation is inferential rather than stated.

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?

Usage is implied by "for a specific asset by symbol" — a single-asset lookup rather than a bulk or historical query — but there is no explicit when-to-use/when-not guidance and no mention of the nearby get_market_cap_history or list_market_caps tools. An agent must infer the routing from the tool name.

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