web_search

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

Annotations already cover safety (readOnly, idempotent, openWorld, non-destructive), but the description adds genuinely new behavioral facts: keyless DuckDuckGo fallback, Brave activation when BRIDGE_BRAVE_API_KEY is set, explicit provider-error reporting, and 'permissions: none'. It does not discuss rate limits or result freshness, keeping it short of a 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?

Front-loaded with purpose and return format, followed by provider and error behavior in tight sentences. The trailing '[v1.0.0; permissions: none]' tag is mildly noisy but carries the useful 'no permissions required' signal.

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 an output schema present and rich annotations, the description needn't explain return values, and it is complete enough to call correctly, including provider fallback behavior. The only real omission is guidance on choosing this tool over web_fetch.

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 75% and the provider enum already documents auto-selection, but the description reinforces the exact key-configured logic that determines Brave vs DuckDuckGo, which is the trickiest parameter to reason about. limit and timeoutMs still get no treatment in the description, so it stops short of a 5.

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 ('Search the public web') and even declares the return shape (titles, URLs, snippets). This cleanly separates it from the sibling web_fetch, which retrieves a known URL rather than discovering one.

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?

The description implies when it applies (finding web sources) and explains provider selection, but never states when NOT to use it or routes to web_fetch for known URLs. Usage is implied rather than explicit.

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