Validate a list of URLs and return, for each one, whether it is reachable plus its HTTP status and . Use it to check that sources cited in a document still resolve before publishing.
| Name | Required | Description | Default |
|---|---|---|---|
| urls | Yes | Absolute http(s) URLs to check (max 5). |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It usefully discloses the return shape (reachable flag, HTTP status, title), but says nothing about network behavior such as redirect handling, timeouts, or whether the call has any side effects. The cap of 5 URLs is left to the schema.
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, zero waste, and the action plus its returned fields are front-loaded ahead of the usage note.
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 correctly compensates by naming the return fields. For a single-parameter read tool with full schema coverage this is nearly complete; only minor operational details like rate limits or fetch behavior are absent.
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 100% and there is only one parameter, so the schema already documents the URL array and its max-5 limit. The description adds no syntax or format detail beyond what the schema states, making the baseline 3 appropriate.
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 ('Validate a list of URLs') and immediately specifies the per-URL output (reachability, HTTP status, <title>). With no siblings to distinguish from, the purpose is unambiguous.
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 a concrete use case ('check that sources cited in a document still resolve before publishing'), which tells the agent exactly when this tool applies. No exclusions or alternatives are needed since no sibling tools exist.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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