fetch_content

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

With no annotations, the description carries the behavioral disclosure burden and does well: it mentions free usage, real browser rendering, JavaScript support, parallel fetching, and the 10-URL limit. It does not discuss failure behavior, caching semantics, or potential side effects, but for a read-oriented fetch tool the key behavioral traits are disclosed.

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: the core action comes first, followed by only high-value differentiators. Every sentence earns its place, and no unnecessary detail is included.

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 tool with seven parameters and no output schema, the description provides enough orientation to invoke it correctly in most cases. The schema covers parameter details, and the description covers real-world behavior like browser rendering and parallel fetching. Minor missing context includes default caching and output format behavior, but these are partially covered by schema defaults.

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 the baseline is 3. The description adds a couple of useful constraints like 'Up to 10 URLs' and parallel fetching, but it does not need to explain each parameter because the schema already provides complete descriptions for all seven parameters.

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 begins with a specific action and resource: 'Read one or more URLs and return clean markdown.' It clearly differentiates this from browsing or searching by emphasizing URL-based fetching and positioning it as preferable to curl/raw HTTP for page content.

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 gives concrete usage guidance: 'Prefer this over curl or raw HTTP for page content' and notes that it handles JavaScript-heavy pages. It does not explicitly contrast it with the sibling 'search' tool, but the intent is reasonably clear for an agent deciding between fetching and searching.

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