Web search

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

The annotations already establish read-only, open-world, idempotent, non-destructive behavior, and the description adds valuable context on top: Google's total_results can shrink while paging, corrected_query does not change the actual results, each call consumes one unit of a daily quota, and engine coverage depends on the control-panel configuration. These details go well beyond the structured hints and help an agent predict real behavior.

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 long but every sentence carries distinct information: return fields, pagination, quota, coverage caveats, and the Search Console distinction. It is front-loaded with the core purpose and follows with operational constraints. No sentence is filler or redundant with the schema.

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?

With no output schema, the description compensates by enumerating the returned fields and their caveats. For a 20-parameter tool with one required parameter, it covers what results look like, how pagination works, quota implications, and engine coverage. An agent has enough context to invoke it correctly without guessing.

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 100%, so the baseline is 3, and the description still adds meaning beyond the schema: it explains the next_start pagination mechanism, the 10-per-call/100-per-query limits, and the cost of each call against the quota. This is useful semantic context for choosing parameter values, though the schema itself already documents each parameter well.

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 opens with a specific verb and resource: 'Web search through your Google Programmable Search Engine (Custom Search JSON API).' It clearly conveys this is a web search tool returning query metadata and result items, which distinguishes it from the sibling image search and from Google Search Console. The explicit 'NOT Google Search Console' note further sharpens the boundary.

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 provides clear operational guidance: paginate with next_start, stay within the 100-result window, and prefer one precise query because each call consumes quota. It explicitly says the tool cannot report how your own site is indexed or ranked, a useful when-not-to-use exclusion. It does not explicitly route to search_images or raw_request, so it stops short of naming alternative sibling tools.

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