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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world). The description adds genuinely new behavioral context not in the structured fields: the $0.002 USDC per-call cost via x402, which matters for an agent deciding whether to invoke it. Rate limits and freshness window are still unstated.

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 short sentences, front-loaded with the resource scope and immediately followed by the cost note. No filler, every sentence earns its place.

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 simple, single-optional-param feed with an output schema and full annotations, the definition is nearly complete. The only gap is that the freshness window ('newest') is never quantified.

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 single 'limit' param is fully documented with max and default), so the schema carries the semantics. The description adds nothing about the limit parameter, so baseline 3 is appropriate.

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 (newest submissions) and resource (arXiv quant-ph), so the agent knows exactly what it returns. The category name itself differentiates it from the many other recent-* siblings, but there is no explicit routing language naming those alternatives.

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?

Usage is implied by 'newest submissions in quant-ph' — an agent can infer this is for latest quant-ph papers — but there is no explicit when-to-use guidance, no mention of when to prefer arxiv__search or the all-category arxiv__recent, and no exclusions.

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