vk_fetch_all

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

Beyond the annotations (readOnlyHint, openWorldHint), the description discloses meaningful behavior: it handles multiple pagination styles, manages cursor fields, reads array paths from the catalog, enforces a configurable max_items cap, and returns a structured JSON with a truncated flag. This is rich context for an agent selecting or invoking the 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-organized: a one-sentence high-level summary, a compact explanation of supported pagination styles, and a terse Args list followed by the return shape. Every sentence adds useful information with no filler.

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 7-parameter tool with no schema descriptions, the description is complete enough for correct invocation: it covers operation selection, parameter roles, the automatic catalog lookup, pagination behavior, the safety cap, and the exact return format. The output schema being present further reduces the need for more detail.

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, and it does: every parameter is explained in the Args section, with added semantics such as 'cursor fields are managed', 'override the array path', 'page size to request', and 'hard cap to protect context'. This goes well beyond the bare 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 opens with a specific action: 'Auto-paginate a read endpoint and return every row in one response.' This clearly identifies the verb, resource type and scope and distinguishes it from siblings like vk_call_method or vk_get_raw, which are not auto-paginating or are write-capable.

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?

It gives clear context by requiring operation_id to be 'a read endpoint from the catalog' and explicitly states the auto-pagination behavior, so an agent knows to use it when all rows from a read endpoint are needed. It does not name alternatives or provide an explicit 'when-not-to-use, but the read-only, all-rows purpose is well scoped.

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