cmc_global_metricsAggregates total crypto market cap, dominance, and 24h volume to gauge macro liquidity and overall market conditions.
Aggregate crypto market metrics: total cap, dominance, 24h volume.
A macro/liquidity gauge for the crypto market as a whole (EH-422).
| Name | Required | Description | Default |
|---|---|---|---|
| mode | No | ||
| source_checkpoint | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.3.6Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare that the tool is read-only, open-world, idempotent, and non-destructive, so safety behavior is covered. The description adds the metric scope and macro-gauge framing, but does not disclose data freshness, source, aggregation window, or what 'delta' mode changes.
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 definition is two short sentences and is front-loaded with the core purpose. The internal ticket reference 'EH-422' is noise for an agent, but the rest is efficient.
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?
An output schema and rich annotations reduce the burden, but the description still omits all parameter semantics and provides no sibling differentiation. For a tool with an unexplained 'delta' mode and 'source_checkpoint' input, the definition is not complete enough for confident fuller use.
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 two parameters with 0% schema description coverage, and the description does not mention either 'mode' or 'source_checkpoint.' It therefore adds no meaning beyond the schema and leaves the delta/checkpoint behavior unexplained.
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 uses a specific verb and resource: 'Aggregate crypto market metrics,' and lists the key outputs: total cap, dominance, and 24h volume. It is clear what the tool returns, but it does not differentiate itself from siblings such as coinglass_macro_snapshot or cmc_quotes.
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?
Calling it 'A macro/liquidity gauge for the crypto market as a whole' implies when it is useful, namely for broad market or liquidity assessment. However, it gives no explicit when-to-use guidance, exclusions, or comparison to sibling macro tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.