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

The annotations only cover read-only safety, so the paid-access disclosure — $0.01, x402, USDC on Base — is genuinely additive and tells the agent a monetary side effect exists. Gaps remain: no mention of what a response contains (multiple matches? confidence?), no partial-match behavior, and no failure/no-record handling.

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 short sentences, each earning its place: what it returns, when to use it, and what it costs. The most decision-relevant information (who renewed / when) is front-loaded.

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 and no parameter descriptions, the description should ideally explain the shape of a hit and how the free-text inputs combine. It covers purpose, use case, and cost well, but an agent still cannot predict result structure or how to narrow a query beyond guessing.

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 0% for all four parameters (year, title, author, limit), so the description carries the burden and mostly does not. Only the year parameter is indirectly constrained by the "1929–1963" range; it says nothing about whether author means the original author or the renewer, how title matching works, or what limit does.

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?

"Find who renewed a 1929–1963 work's US copyright and when" gives a specific verb, resource, and date scope, plus the expected answer (current rightsholder or estate). This is clearly distinguishable from the sibling status-check tools, which deal with public-domain determination rather than rightsholder identification.

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?

"Use when you need to know whom to ask for permission or a license" states a concrete decision context, which is strong for routing. It stops short of exclusions or naming a sibling as the alternative for adjacent questions (e.g. whether a work is in the public domain), leaving some inference to the agent.

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