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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering safety. The description adds valuable behavioral context beyond annotations: cost ($0.05), required API key, and the specific data fields returned. This goes beyond the baseline and helps the agent anticipate side effects (e.g., no on-chain mutations, but a fee is incurred).

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 appropriately sized and front-loaded: it opens with the core purpose, then lists returns, usage guidance, supported chains, and cost. Every sentence adds value, and the structure is logical, though it could be slightly more compact.

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?

With no output schema, the description must explain return values, and it does: balance, age, entity label, transaction history summary, token holdings, and risk flags. It also covers auth requirements (API key) and cost. It is sufficiently complete for an agent to invoke correctly, though it could specify the exact format of the report.

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%: both 'address' and 'chain' have detailed descriptions in the schema, including an example and supported chain list. The description adds no new parameter-level details beyond what the schema already provides, so a 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 clearly states the tool's function: 'Forensic address intelligence report via Blockscout multi-chain.' It specifies the resource (address intelligence) and the verb (investigate), and distinguishes itself from siblings by listing specific outputs like balance, entity label, and risk flags, which no other sibling tool mentions.

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 provides clear when-to-use guidance: 'Run before sending USDC to any unknown address.' It also lists supported chains, giving context for applicability. However, it does not explicitly name alternative tools or state when not to use it, so it stops short of a 5.

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