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

The annotation already declares readOnlyHint=true, destructiveHint=false, so the agent knows it's safe. The description adds that the data is 'Live', indicating real-time freshness, and enumerates the exposed metrics. No annotation contradiction; the description aligns with the safe, idempotent, read-only profile.

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?

Two sentences, zero wasted words. The first sentence front-loads the core purpose and key data categories. The second sentence adds clear guidance on when to call. Every word earns its place; no repetition of annotation fields (title, hints).

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?

Despite the tool having no parameters and an existing output schema, the description covers all necessary context: what data it provides (TVL, chains, stablecoin cap) and when to use it (DeFi flows, liquidity, risk appetite). The agent can decide to call or skip without additional blanks.

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 input schema has 0 parameters, so baseline is 4 per guidelines. Description correctly states the tool returns TVL, top chains, and stablecoin cap – these are output concepts, not parameters. Since no parameters exist, the description cannot add parameter meaning, but it appropriately describes what the tool returns without needing param info.

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 clearly states 'Live DeFi overview: total value locked (TVL), top chains by TVL and stablecoin market cap.' This provides a specific verb ('overview') and resource ('DeFi'), and lists concrete metrics. It differentiates from sibling tools like get_crypto_market (general crypto) or get_market_dominance (dominance) by focusing exclusively on DeFi liquidity metrics.

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 includes explicit use-case guidance: 'Call for DeFi flows, liquidity and dry powder, or risk-on/risk-off reads.' This tells the agent when to choose this tool over siblings. However, it does not mention any prerequisites or limitations (e.g., data update frequency, supported blockchains), which would improve the guideline further.

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