fetch_content

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

No annotations are provided, so the description carries the full burden. It discloses that content is untrusted, mentions pagination via start_index and max_length, and describes backend options with their tradeoffs. It doesn't mention potential errors, rate limits, or encoding details, but covers the key behavioral aspects for a fetch 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?

The description is well-structured with a clear purpose statement, a brief usage note, and an Args section that explains each parameter. It's concise for the amount of content it covers, though the backend description is slightly long. The key details are front-loaded.

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?

The tool has an output schema (not shown but mentioned), so return values are presumably documented there. The description covers the essential calling context: URL format, pagination, backend selection, and security note. For a fetch tool that may hit external urls, this is fairly complete, though it doesn't mention error handling or response structure beyond the schema.

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%, so the description must compensate. It provides clear semantics for url (must start with http/https), start_index (character offset), max_length (max characters), and backend (with options and implications). All parameters are explained beyond the schema definitions (which only have titles and types).

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 the tool fetches and extracts main text content from a webpage, stripping out non-content elements. It explicitly mentions it's used after searching to read full content of a specific result, distinguishing it from the sibling search tool.

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 provides context for when to use it ('after searching to read the full content of a specific result') and includes a note about treating content as untrusted input. It doesn't explicitly exclude alternatives or state when not to use it, but the context is clear enough given the sibling is a search tool.

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