Gemini Web Fetch

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

With no annotations, the description bears full burden. It discloses one useful trait: invocation may not actually trigger a fetch because the model decides. But it says nothing about the effects of yolo, approval_mode, checkpointing, include_dirs, or timeouts, which are potentially impactful behavioral knobs on a 9-parameter tool.

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 short sentences, front-loaded with the mechanism and followed by the caveat. No filler, though the caveat sentence could be worked into a fuller description rather than standing alone.

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 9-parameter wrapper with a rich output schema and no annotations, the description is far too thin. It need not explain return values, but it must explain the safety-relevant and behavior-altering parameters it leaves entirely undocumented.

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% across 9 parameters. The description only gestures at urls and prompt; the remaining seven parameters (yolo, model, timeout_s, extra_args, include_dirs, approval_mode, checkpointing) are undocumented in both schema and description. No compensation for the coverage gap.

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 says it injects URLs into a prompt to trigger CLI WebFetch, which is a recognizable verb+resource. However, 'convenience wrapper' is meta rather than descriptive, and the second sentence muddies the purpose by stating that the model, not the caller, decides whether WebFetch actually runs. An agent cannot confidently tell what calling this tool accomplishes relative to the sibling WebFetch.

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?

There is no statement of when to use this tool versus the sibling WebFetch, gemini_prompt, or GeminiGoogleSearch. The note that WebFetch is a CLI built-in and the model decides whether to call it is a behavioral caveat, not usage guidance.

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