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

Despite readOnlyHint=true already covering safety, the description adds substantial behavioral context: the score is a composite z-score vs 30-day baselines, data is daily since 2015, returns include per-component attribution and methodology_version, and it explicitly cautions it's not a trading signal. It also notes update frequency. This goes well beyond annotation basics.

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 efficiently packed: it starts with the core return value, then the methodology, then use cases, then a caveat, then update frequency. No redundant sentences or filler; each clause adds information.

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 metric tool with one optional parameter and no output schema, the description gives a comprehensive picture: what is returned (score, attribution, context tiles, methodology), when to use it, when not to, historical depth, and update cadence. It covers all key aspects an agent needs for selection and 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 description coverage is 100% for the only parameter 'days', with clear meaning (history series length) and constraints (max 1825, Gold tier). The main description does not elaborate on the parameter, but that is acceptable when the schema is fully descriptive. Baseline of 3 applies.

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 opens with a specific verb and resource: 'Returns a 0-100 Ethereum network sentiment score' with precise methodology (composite z-scores of active addresses and transaction count vs 30-day baselines). This clearly distinguishes it from generic sentiment tools by specifying Ethereum on-chain activity.

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?

Explicit guidance is given: 'Call when the user asks about Ethereum on-chain activity, ETH network demand heating up or cooling off, or address/transaction trends, or when timing launches, deployments, or gas-sensitive operations.' It also states when not to rely on it: 'Directional indicator, not a trading signal.' This covers when/when-not comprehensively, though no alternative tool is named.

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