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

With no annotations, the description carries the full behavioral burden. It discloses that per-wallet estimates are paid calls ($0.003 via x402 or card pass) and adds a notable conflict-of-interest disclosure ('We hold UBI and say so'). However, it does not state that the tool is read-only, has no side effects, or describe rate limits or authentication, leaving important behavioral traits implicit.

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 a dense, run-on sentence with nested parentheticals and multiple topics (free data fields, paid call, website parity, holding disclosure). It front-loads the data fields but could be broken into clearer sentences. Some elements, such as the website-parity note, are terse, while the overall length is not excessive for the amount of 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?

There is no output schema, so the description must explain return values; it does by listing key data points (USDC waiting, payout list validity, USDC per 1M UBI, recent payouts). It also covers the paid per-wallet estimate path and a conflict-of-interest note. It omits what happens when address is omitted, but that behavior is strongly implied.

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%, so the baseline is 3. The description adds meaningful detail beyond the schema: the optional address parameter triggers a paid call at a specific URL, costs $0.003 via x402 or card pass, and returns the same numbers as the public website. This is useful semantic enrichment for the single optional parameter.

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 resource: UBI holder payout data on Arc, listing specific fields (USDC waiting, next valid payout list, USDC per 1M UBI, recent payouts). It does not name a sibling for differentiation, but the tool is unique among the large sibling set. The purpose is clear, though it lacks a direct verb like 'get' or 'list'.

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?

It distinguishes the free aggregate data this tool provides from the per-wallet payout estimate, which it explicitly marks as a separate paid call with URL and price. This gives clear context for when to use this tool versus the paid alternative. No explicit when-not-to-use condition or sibling tool is named, but the paid-call boundary is useful.

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