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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that: it is v4-only, returns per-sample data over a time window, and is protocol-wide rather than wallet- or reserve-scoped. It does not describe output shape or pagination, but this is minor for a read-only query tool.

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?

Three tightly packed sentences with no filler. The most important scoping fact ('v4 only') is front-loaded, followed by the key metrics, then clear routing guidance. Every sentence earns its place.

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 read-only, zero-required-parameter history tool, the description provides everything needed to select and invoke it correctly: scope, metrics, time-window concept, cross-chain behavior, and sibling differentiation. The annotations cover safety and the schema covers parameter details, so nothing critical is missing.

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?

Schema coverage is 100%, so the schema already documents all three parameters in detail. The description reinforces key semantics like omitting chainId for all chains and the per-sample window concept, but it does not add substantial meaning beyond what the schema provides. Baseline 3 is appropriate.

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 states a specific verb ('get'), resource ('protocol-history'), and scope ('Aave v4 protocol-wide history') with concrete metrics: market size, total borrows, available liquidity. It explicitly distinguishes itself from sibling tools get_user_summary_history and get_apy_history, making it immediately clear what this tool is and is not.

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 gives explicit usage direction: 'Use this for "is the protocol growing"' and names the exact alternatives to use instead for wallet-level or reserve-level history. It also clarifies how to cover all chains by omitting chainId, leaving no ambiguity about invocation context.

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