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

With no output schema, the description carries the burden of explaining return behavior, and it does so richly: results are fused by reciprocal rank, deduplicated by normalized URL, grouped under also_on, and tagged with publisher and source engines. It also discloses that the service is keyless and that task_context tunes results, which goes well beyond the readOnlyHint and destructiveHint annotations.

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?

The description is two sentences with no filler. The first sentence packs every meaningful behavioral detail into a compact list, and the second sentence immediately tells the agent when to use an alternative.

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?

Given the absence of an output schema, the description fully compensates by explaining sources, result structure, deduplication, grouping, and provenance signals. It also covers usage context and keyless access, making it sufficiently complete for an agent to invoke the tool 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 coverage is high at 83%, so the schema already documents most parameters. The description adds little parameter-level detail beyond the schema's own descriptions, and the one undocumented parameter, limit, still has clear min/max/default constraints in the schema.

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?

The description states a specific verb and resource: it is a news search fusing Google News RSS and Bing News RSS. It goes beyond the tool name by explaining the fusion, deduplication, and grouping behavior, and it explicitly distinguishes itself from feed_items for single-site post retrieval.

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?

It explicitly says to use this tool for 'what is the news about X' and routes single-site post needs to feed_items. This gives an agent a clear decision rule between the search tool and a sibling, though feed_find is not directly addressed.

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