Global market summary

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

Annotations already indicate readOnly, idempotent, non-destructive. Description adds that it returns summary metrics, which is useful but doesn't disclose further behavioral traits like caching or performance. No contradictions.

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?

Single, front-loaded sentence that efficiently conveys the tool's purpose. No wasted words, and the structure is optimal for quick comprehension.

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?

Given no parameters and an existing output schema, the description fully covers what an agent needs to know: it returns aggregated market metrics. The listed items (market cap, volume, dominance, trend) are sufficient for understanding the scope.

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?

No parameters, so schema description coverage is 100%. The description adds context about the returned metrics beyond the schema, making it clear what the tool provides without needing param details.

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 it provides a summary of total market cap, 24h volume, BTC/ETH dominance, and recent trend. The verb 'summary' and resource 'global market' are specific. It distinguishes from siblings like coin_markets (individual coins) and top_coins (list) by being an aggregated overview.

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?

Implied usage for a quick overview of global market metrics, but no explicit guidance on when to use vs. alternatives like coin_markets or fear_greed_index. No exclusions or caveats mentioned.

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