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

With no annotations provided, the description carries the burden of behavioral disclosure. It adds useful context: default 30-day range, APY in percent units, and cost per call. But it does not explain the response format, data granularity, failure behavior, or how pool_uid is obtained, leaving significant gaps.

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 two concise sentences with a parenthetical cost note. It front-loads the core function, provides usage guidance, and adds practical billing info without unnecessary words. Every sentence contributes value.

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?

Given no output schema and no annotations, the description should explain what the tool returns, but it only vaguely says 'time series'. It omits details like whether both APY and TVL are returned separately, data point frequency, and how to interpret results. For a paid tool, this is a notable gap that could hinder correct invocation.

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 0%, so the description must compensate. It mentions pool_uid as the target pool and 'default 30d' which clarifies the days parameter's meaning and default, but it does not explain parameter bounds, format, or that days is optional with constraints. This is insufficient for such low schema coverage.

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 the tool's function: providing per-pool APY/TVL time series for trend and volatility analysis of a single pool. It specifies the resource (Barker's index), scope (one pool_uid), and default period, distinguishing it from sibling tools like barker_pool_detail or barker_market_trend that likely offer different data.

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 explicitly says 'Use for' with concrete example queries ('is this pool's APY stable', '这个池子收益稳不稳'), giving clear usage intent. However, it does not mention when not to use it or alternatives, so it falls short of the full 5-point criterion.

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