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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds meaningful context: data comes from CDP-indexed events, distinguishes active vs ended announcements, and explains the x402 payment requirement with prepaid-header and free-call options. This is valuable beyond the annotations.

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 information-dense and starts with the core purpose, which is good. However, it packs many distinct topics—announcement structure, indexing source, issuer-communications positioning, pricing, payment options, rate limits—into a single run-on paragraph, making it harder for an agent to parse the most decision-relevant facts quickly. It could be split into purpose and usage/pricing sections.

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 one parameter, full schema coverage, and an output schema, so the description doesn't need to explain return values. It covers the data source, the active-vs-ended distinction, the payment mechanism, and the target use case. Minor omissions are things like chain/network specificity and what to do if the address has no announcements, but these are not critical given the output schema exists.

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%: the only parameter, address, is described as 'B20 Asset token address'. The description adds no additional format, chain, or example details for the address, so it doesn't raise the score above the baseline. The description does reinforce that address is the required input, but that's already in the schema.

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 identifies the tool as reading on-chain issuer notices and corporate actions for B20 Asset tokens, and explicitly contrasts it with ERC-20 channels, which helps distinguish it from sibling tools. The verb 'Reads a token's announcement feed' plus the concrete 'Announcement: id, description, uri' structure makes the resource and operation unmistakable.

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 this is the issuer-communications primitive for B20/RWA token holders and states the required input (address) and pricing model. It doesn't explicitly name alternative tools or state when not to use it, but the B20-specific scope and 'ERC-20 has no equivalent for' contrast imply the appropriate context. The pricing and free-tier guidance also help the agent decide whether to call it.

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