Google Lens

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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds real context: the request is proxied through Decodo's Web Scraping API and results come back as parsed JSON. It omits any mention of credentials, quota/rate limits, or latency of the rendering path, so not a full 5.

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?

Two sentences, front-loaded with the action and scope, with the docs link trailing where it belongs. Slightly dense — the API and target-name detail could be trimmed — but every clause carries information.

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 3-parameter, no-output-schema tool, the description tells the agent the return type (parsed JSON visual matches) and the execution path (Decodo proxy). An agent can call it correctly; only error/auth behavior and result structure detail are absent.

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% with enum and defaults documented, so the baseline is 3. The description only implies that `query` is an image URL and says nothing about `jsRender` or `deviceType` beyond what the schema already states.

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 (run) and resource (Google Lens image search on an image URL) and names the backend target (`google_lens`). The image-URL dimension clearly separates it from the text-oriented siblings like google_search and search.

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?

Gives two concrete use cases: identify what an image shows, or find pages where it appears. That's clear context, but no explicit when-not or named alternative is offered, so it stops short of the 5 bar.

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