check_mirrors

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

With no annotations provided, the description carries the full burden. It discloses critical behavior: uses a health cache, force_refresh bypasses cache, and URL filtering (only public/allowlisted). This adds significant value beyond the schema. However, it does not explicitly state whether the operation is read-only or any side effects.

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 concise sentences with no fluff. The most important information (purpose, caching, URL restrictions) is front-loaded. Every sentence adds value.

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 tool with two parameters and no output schema, the description covers purpose, behavioral constraints, and parameter hints. It lacks explicit description of return values, but given the context, it is mostly complete for an agent to use correctly.

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 explains force_refresh's effect (ignores cache) and implies that the 'urls' parameter accepts only public/allowlisted URLs. However, it does not fully describe all parameter meanings or expected formats, leaving some ambiguity.

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 it 'probes Sci-Hub mirrors for availability', which distinguishes it from sibling tools like 'list_mirrors' that likely list mirrors. It also mentions caching and force_refresh behavior, making the tool's specific purpose unmistakable.

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 useful usage context: it only probes configured public mirrors or allowlisted https hosts, rejecting private/localhost URLs. This helps the agent determine when to use this tool and what inputs are valid. However, it does not explicitly compare to other tools like 'list_mirrors' or 'download_paper'.

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