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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: it clarifies the score's scope boundaries (not an audit, not a transaction guarantee) and what feeds it, which prevents misreadings. It stops short of detailing freshness, coverage latency, or scoring methodology, so it is not a 5.

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 sentences with zero filler, front-loaded with the definition, then the use case, then the exclusions. Each sentence earns its place and the ordering follows the reader's decision path.

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?

An output schema exists, so return-value detail is not needed. For a one-parameter, read-only aggregate the description supplies purpose, usage trigger, exclusions, and scope limits, leaving nothing an agent needs in order 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 description coverage is 100% with a single optional 'chain' parameter defaulting to base, so the schema carries the parameter documentation. The description's 'single-chain' framing implies exactly one chain is scoped, but it adds no syntax, default, or accepted-value detail beyond the schema. 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?

States a specific resource and scope: a 'chain health score' aggregating three named inputs (gas data, protocol TVL, stablecoin stability). It also distinguishes itself from siblings by explicitly excluding contract audits, transaction guarantees, risk analysis, and block facts, so an agent can route correctly without opening a schema.

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?

Gives an explicit when-to-use ('single-chain operating snapshot before choosing where to act') plus when-not-to-use, naming concrete alternatives: security.contract.scan and token.risk for safety, chain.block for block facts. Both the trigger and the exclusions are spelled out.

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