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

Annotations already cover readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is free. The description adds a genuinely non-derivable fact: a $0.002 USDC per-call cost via x402. It stops short of noting any rate limits, ordering guarantees, or freshness/latency of 'newest'.

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, zero filler, with the core purpose front-loaded and the cost caveat second. Nothing is redundant with the title or 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?

An output schema exists, so return-shape explanation is unnecessary, and the schema carries parameter detail. For a two-parameter read tool the description plus structured fields are close to sufficient; only the routing-versus-siblings question is left unaddressed.

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% — both 'limit' (max 50, default 25) and 'category' (e.g. math.PR) are documented in-schema. The description adds nothing about parameter syntax or validity, so the 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+resource (newest submissions) and scope (any arXiv category). 'Any category' implicitly separates it from the hard-coded sibling category tools like arxiv__recent-cs-ai, though it never names them, so the differentiation is inferred rather than stated.

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 guidance on when to choose this over arxiv__recent-cs-ai (a fixed category) or arxiv__search (keyword queries). The agent must infer routing from the sibling names alone, which is exactly the gap the description should fill.

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