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

With no annotations provided, the description carries the full burden, and it does disclose meaningful behavior: results are merged and de-duplicated across three providers, and each call costs $0.005 USDC via x402 on Base. It omits error/empty-result behavior and pagination, but the pricing and aggregation semantics are substantial added value.

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?

Two sentences, zero waste, with the core purpose front-loaded and the cost disclosure placed second. The field enumeration earns its space because there is no output schema.

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?

For a 7-param search tool with no output schema, the description usefully enumerates what comes back and discloses cost, which are the two things the schema cannot convey. The remaining gap is disambiguation from the near-identically named sibling tools.

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 all seven parameters are already documented with allowed values and defaults. The description adds no further parameter semantics (e.g., how sort interacts with merged sources, or how openAccess behaves for arXiv vs Crossref). Baseline 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: 'Search scholarly papers across OpenAlex, arXiv and Crossref (merged, de-duplicated)', and enumerates the returned fields. It does not distinguish itself from the sibling 'research_paper' (singular) or 'research_related_papers', so an agent can't fully resolve which one fits a given need from the description alone.

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?

No explicit when-to-use or when-not-to-use guidance. Usage is only implied by the multi-source keyword search framing. The presence of closely named siblings (research_paper, research_related_papers) makes the absence of routing guidance a real gap.

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