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

Annotations already cover read-only and non-destructive behavior. The description adds valuable behavioral context beyond annotations: the operation is paid, restricted to public URLs, and results are isolated so partial failures do not fail the whole batch. This is meaningful additional transparency, though it does not detail failure output 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?

A single front-loaded sentence communicates the action, scope, cost, and failure-isolation behavior with no filler. Every phrase earns its place, and the most important operational detail ('one paid call') appears early.

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 description is adequate for a basic call: it identifies what is checked, the URL limit, the paid nature, and partial-failure isolation. However, it leaves expectedStatus undocumented, says nothing about the result format, and does not explicitly route agents between using this tool and the single-URL check_url alternative.

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 for parameter semantics. It adds the 'public URLs' constraint and 'up to ten' count, which helps understand the urls parameter, but it entirely omits expectedStatus and its intended role. The optional status parameter remains unexplained, leaving a real semantic gap.

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 a specific action ('Check'), a resource ('up to ten public URLs'), and a key differentiator from siblings ('in one paid call', 'isolated results for partial failures'). It distinguishes itself from the single-URL check_url sibling by emphasizing batching and partial-failure isolation.

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 conveys the intended batching use case: checking multiple URLs in a single paid call rather than calling the single-URL tool repeatedly. It does not explicitly name alternatives or state when not to use it, so it falls short of full exclusion guidance, but the context is clear.

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