Raw Custom Search API call

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, and the description reinforces these by stating 'The API has GET endpoints only, so nothing here can modify data.' It also discloses auth behavior (key added in a header, engine id auto-filled), which is valuable beyond the 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 concise but information-dense, front-loading the purpose ('Escape hatch') and then efficiently covering usage, examples, auth behavior, and safety. Every sentence contributes value.

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 single-parameter escape-hatch tool, the description is complete: it specifies the path format, the base URL, the response shape, the parameter coverage gap it fills, and the safety guarantees. No output schema exists, so the description appropriately carries the burden of explaining the return envelope.

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% and the schema already documents the path parameter. The description adds meaningful context with the relative-to-base URL clarification, an example path, and side behaviors like automatic key/engine-id injection, which goes beyond the bare 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 precise verb and resource: 'performs a GET against any Custom Search JSON API path and returns the raw, unnormalized response envelope.' It also distinguishes itself from typed sibling tools by explicitly targeting parameters the typed tools do not expose.

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 gives an explicit when-to-use condition: 'Use it for parameters the typed tools don't expose (lowRange/highRange, c2coff, hq, fields).' It also provides a concrete example path and explains how the API key and engine id are handled, making the invocation context unambiguous.

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