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

With no annotations, the description carries the full burden. It clarifies that inflows are a TVL-based net change, explicitly noting that positive equals net inflow and negative equals outflow, and that yield is included—a non-obvious behavioral nuance. This goes beyond the function name and provides valuable context for interpreting results.

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, well-structured paragraph that leads with the core purpose, then details the metrics and the inflow semantics, and ends with usage notes. Every sentence carries information; there is no padding or repetition.

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?

The tool has no output schema, so the description must convey the return content, which it does (TVL low/high, APR, APY, inflows). It also explains the inflow metric's meaning and the optional period. While it omits details like exact response format or pagination, the information is sufficient for an agent to understand what the tool returns and how to call it correctly.

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 both parameters. The description adds value by referencing list_vaults for strategy_id and clarifying the omission behavior for period, which enriches the parameter meaning beyond the schema's basic enum listing.

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 action (get aggregated stats) on a clear resource (vault stats) with defined content (TVL, APR, APY, inflows). It distinguishes itself from siblings like get_vault and get_vault_history by specifying the windowed aggregation, making its purpose unambiguous.

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 tells the agent to use strategy_id from list_vaults, which is a direct cross-tool reference, and explains that omitting period returns all windows. However, it does not explicitly state when NOT to use this tool or contrast it with alternatives like get_vault_history, so it falls short of a full 5.

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