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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely useful non-annotation context: a per-call cost of $0.002 USDC via x402, which affects how freely an agent calls it. No rate limits or result freshness window are given.

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 tight sentences with zero waste: purpose first, cost second. Nothing redundant or padded.

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 one-optional-param tool with an output schema and rich annotations, the description covers purpose, category scope, ordering ('newest') and cost. It need not explain return values since an output schema exists; only freshness/pagination nuance is left implicit.

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% and the single 'limit' parameter (max 50, default 25) is fully documented in the schema. The description adds nothing about limit 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+resource with an explicit scope: 'newest arXiv submissions in cs.RO (Robotics)'. The category label is what distinguishes it from the dozen recent-* siblings, so an agent can route correctly, though it never names an alternative explicitly.

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' – fetch the latest robotics papers – but there is no when-to-use vs when-not guidance and no pointer to arxiv__search or arxiv__recent for broader queries. Adequate but not explicit.

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