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

Annotations already declare readOnlyHint=true, so the safety profile is covered; the description still adds that results come from multiple engines, are aggregated snippets, and that output is JSON with hits and metadata. It does not mention rate limits, engine variability, or result ordering, so it stops just short of the top marks.

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?

Four labeled lines, each doing a distinct job, with the routing rule front-loaded ahead of composition notes. The "Returns:" line partly duplicates the existing output schema, which is the only wasted content.

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 an output schema, full annotation coverage, and only two parameters, everything the agent needs to choose and call the tool is present: purpose, inclusion/exclusion criteria, and downstream composition with smart_fetch and smart_pipe.

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 both query and max_results are already documented (including the 1–50 range and default of 10). The description adds no syntax, quoting, or operator guidance for the query string, so the baseline 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 and resource ("Run multi-engine web search and aggregate snippets") and contrasts with the sibling smart_fetch by noting the URL condition. An agent can distinguish it from smart_fetch without opening either 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?

Explicit "When to use" and "When NOT to use" lines, and the exclusion names the exact alternative (smart_fetch) plus the condition (user already supplied the exact URL) that selects it. Nothing is left to inference.

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