DeepSeek Web Fetch

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

Annotations already cover readOnly/openWorld/non-destructive, so the bar is lower, and the description adds real value: the untrusted-content/prompt-injection warning and the cached-continuation behavior of next_offset. It does not disclose failure modes for non-public URLs or rate limits.

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?

Four tight sentences, front-loaded with the core action, with no filler. Each clause carries distinct operational information (scope, units, continuation, safety).

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 no output schema, the description still conveys the return format (Markdown) and the pagination model. It is nearly complete for a read-only fetch, missing only error/edge-case behavior.

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 carries the burden. It usefully clarifies that offset and max_chars are measured in Unicode code points and points to next_offset, but it omits url constraints (public pages only, length bounds) and the default/max values for the paging params.

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 ('Fetch one public HTTP/HTTPS page as Markdown') plus the backing service ('DeepSeek's official Fetch API'). It also differentiates itself from the built-in WebFetch, so an agent can route correctly without opening the schema.

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?

Gives clear context: fetch a single page, use next_offset for continuation, and this is distinct from built-in WebFetch. It stops short of an explicit when-not/alternative statement against the sibling deepseek_search, leaving that routing to inference.

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