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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds a genuinely non-obvious behavioral trait the annotations omit: a per-call cost of $0.002 USDC via x402. It omits pagination/rate behavior, but an output schema exists and the feed is capped at 50 results.

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 what the tool returns and followed by the cost disclosure. Every clause earns its place; there is no filler.

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 read-only category feed with zero required parameters and an output schema, the description covers purpose and cost adequately. It would be fully complete if it hinted at how it differs from the sibling feeds or the pagination cap, though neither is strictly required to call it correctly.

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% for the single `limit` parameter ('Results, max 50 (default 25)'), so the schema already carries the semantics. The description adds nothing about limit, which is the correct baseline 3 when structured fields do the heavy lifting.

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 resource (newest arXiv submissions) with the exact category code and human-readable expansion (cs.CR, Cryptography and Security). This lets an agent distinguish it from the twelve sibling category feeds (cs.AI, cs.CL, astro-ph, etc.) without opening any schema.

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?

The description gives no when-to-use guidance, no exclusions, and never mentions the alternatives. It does not say to use arxiv__paper for a specific paper or arxiv__search for keyword queries, leaving routing entirely to inference from the name.

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