web_fetch_exa

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds behavioral context beyond annotations, such as the ability to batch multiple URLs in one call and the return of clean text plus metadata.

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 compact and front-loaded with the core purpose. It uses a clear structure with 'Best for' and 'Returns' sections, and each sentence serves a distinct purpose without unnecessary detail.

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 relatively simple read-only tool, the description covers the essential context: what it does, when to use it, batching capability, and return value type. The annotations handle safety, and the schema covers parameters, leaving no significant gaps for an agent to select and invoke the tool.

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%, so both parameters (urls and maxCharacters) are fully documented in the schema. The description reinforces batching behavior for the urls parameter but adds no new semantic details beyond the 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 clearly states 'Read a webpage's full content as clean markdown', which is a specific verb+resource combination. It also distinguishes itself from sibling web_search_exa by focusing on fetching full content from URLs rather than searching.

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?

Explicitly says 'Use after web_search_exa when highlights are insufficient or to read any URL', providing a direct usage context and alternative. The 'Best for' note further clarifies when to use the tool.

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