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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, and the description goes well beyond them: it discloses the 0.005 USDC per-call x402 cost with the accepted chains, the CC0 data source, and the caveat that the abstract is only present where OpenAlex holds it. This is exactly the payment/coverage context an agent needs before invoking a paid tool.

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 front-loaded sentences that move from trigger to payload to invocation format to cost. Slightly redundant on the DOI path detail, which the schema already covers, but nothing is wasted.

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 values need no elaboration, and the description still flags the abstract-coverage caveat. Combined with the explicit pricing model and path formatting, an agent has everything needed to call this correctly on the first attempt.

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?

With a single parameter at 100% schema coverage, the schema already documents the DOI format including the %2F alternative. The description's path example ('/api/paper/10.1038/nature14539') restates that without adding new semantics, so the baseline of 3 applies.

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 verb and resource ('the paper behind a DOI') and the exact return payload. However, it never distinguishes itself from the sibling get_papers, so an agent choosing between the singular and plural tools gets no help from the description.

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 an agent needs the paper behind a DOI' gives a clear trigger condition. It lacks any when-not guidance or explicit routing to get_papers, but the usage context itself is unambiguous.

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