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

No annotations are provided, so the description carries the full burden. It does disclose content scope (support matrix plus deprecated operators), which is useful behavioral context, but says nothing about whether the call is read-only, its cost/rate profile, or how results are shaped.

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?

A single compact sentence with the subject (operators) and the covered engines front-loaded, followed by the extra scope of deprecated operators. No filler, though the parenthetical example list is slightly dense.

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-parameter, no-output-schema lookup tool the description is adequate about what is compared, but it omits how the optional engine parameter filters the result and what an unfiltered call returns, leaving a meaningful gap.

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 0% for the single 'engine' parameter, so the description must compensate. It does name all four engines in prose, matching the enum, but adds no format or semantics beyond that — notably it never explains that engine is optional or what an omitted engine returns.

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 names a specific resource — search operator support across Google, Bing, Yahoo and Baidu, plus deprecated operators — and lists concrete examples (site:, filetype:, intitle:, before:). It is distinguishable from siblings like build_search_urls or serp_preview, though the verb is implied (a lookup/reference) 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?

Usage is only implied: an agent can infer you call this when you need to know whether an operator works on a given engine. There is no explicit when-to-use statement, no mention of alternatives such as build_search_urls for constructing queries, and no exclusions.

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