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

Goes well beyond the readOnly/openWorld annotations: discloses ordering, de-duplication, per-item wire tagging, that only headlines/links/dates/summaries are returned, that it is public RSS requiring no key, and the exact cost model ($0.003 USDC per successful call via x402 on Base/Solana/Arc, failures uncharged). That pricing and billing-failure detail is exactly the kind of context an agent cannot infer.

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?

Single front-loaded paragraph that opens with what the corpus is before listing ordering, filtering, fields and price; nearly every clause carries information. It is dense to the point of being a run-on, and the field-restriction note slightly overlaps the output schema, but nothing is wasted.

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?

Covers sources, ordering, dedup, filtering, returned fields, auth model and payment terms for a read-only search tool, which is everything an agent needs before invoking it. An output schema exists, so return-value structure need not be described.

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 three parameters are already documented, making 3 the baseline. The description corroborates the filter behavior (keyword match on title/summary, per-item wire tags) but adds no syntax or format detail for limit or the comma-separated wires list beyond what the schema states.

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 concrete verb+resource and pins down scope precisely: press releases merged from three named wires (PR Newswire all-news, Business Wire M&A, Newswire.com). That merged scope differentiates it from single-wire siblings such as search_pr_newswire and search_prnewswire_press_releases.

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 merged-source scope plus 'keyword filter on title/summary' and 'newest first, de-duplicated' clearly signals when this is the right tool (broad multi-wire coverage rather than one publisher). However, it never explicitly says to prefer a single-wire sibling when only one publisher is needed, nor names any exclusions.

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