Check z-library download quota

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

With no annotations provided, the description carries the burden, and it does well by stating that 'does not consume any allowance'—a key safety guarantee for a quota-check operation. It also implies the output fields (used, cap, remaining). It doesn't mention authentication requirements or error behavior if not logged in, which is a minor gap.

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?

Two sentences deliver the core purpose, usage triggers, and side-effect profile without any filler. The most important information (what it checks) is front-loaded, followed by when to use it and the safety guarantee—every clause earns its place.

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 simple zero-parameter tool without an output schema, this description is quite complete: it lists the returned values (used, cap, remain) and when to call it. The main omission is whether authentication is required before calling, given the account-specific nature and the existence of zlib_login as a sibling.

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?

The input schema is empty with 100% coverage, so there are no parameters to describe. The description redundantly notes 'Takes no arguments,' which adds no semantic value but does confirm the expectation. A baseline of 4 is appropriate for zero-parameter tools.

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 uses a specific verb ('Check') and clearly identifies the resource: the z-library account's daily download allowance. It details exactly what information is provided (used today, daily cap, remaining), which sets it apart from the sibling tools focused on searching, downloading, or logging in.

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 explicitly says when to call the tool: before a batch of downloads, or when a download fails with a quota error. It doesn't mention when not to use it or point to alternatives, but given there are no sibling tools that check quotas, the guidance is clear and sufficient.

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