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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior: the data is a cached CCPEDIA sync, not a live exchange feed, with a captured_at timestamp — freshness semantics an agent needs to interpret staleness. It stops short of stating refresh cadence or staleness limits.

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?

Front-loaded with the verb and the hard scope constraint, then the field list, then the caveats. It is a single dense block with nested parentheticals, which is slightly harder to scan than it could be, but no sentence is filler.

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 parameters and no output schema, the description carries the full burden and meets it: it enumerates the returned metrics, identifies the asset scope, and discloses the data source and freshness caveat. An agent has everything needed to call it and to interpret 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 tool takes zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The description correctly spends its words on the return payload instead of inventing parameter guidance.

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 cached market snapshot) and enumerates exactly what is returned: USD price, 24h change, market cap, 24h volume, total Canton DeFi TVL, per-protocol TVL. It also draws a hard scope boundary (CANTON COIN / CC only), so an agent can immediately separate it from the rest of the sibling list.

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?

Explicitly states when not to use it ("Cannot price BTC, ETH or any other asset") and names a concrete alternative (a general crypto-price MCP like CoinGecko). No other sibling tool covers price data, so the external routing instruction is the correct guidance here.

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