market_get_global_stats

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description only adds the data scope (global TVL), which is essentially part of the purpose, and does not disclose additional behavioral traits such as data freshness, rate limits, or response size.

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 description is a single, front-loaded sentence that clearly states the action and expected result without any unnecessary words or repetition. It earns its place completely.

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 zero-parameter tool, the description provides adequate context by specifying that it returns total DeFi TVL globally. An output schema is absent, so a bit more detail on the response format could help, but for a simple statistics endpoint this is largely sufficient.

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 has zero parameters and schema coverage is complete. With no parameters to explain, the description does not need to add parameter semantics, and a baseline of 4 is appropriate for a no-parameter tool.

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 a specific action ('Fetch aggregate global DeFi market statistics') and resource ('DefiLlama'), and explicitly mentions the return value ('total DeFi TVL across all chains and protocols'). This distinguishes it from sibling tools that focus on individual chains or protocols.

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?

It implies usage for a macro view of the DeFi ecosystem, but does not explicitly state when to use this tool versus alternatives like market_get_chain_tvl or market_get_top_protocols. No exclusionary or alternative tool references are provided.

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