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

With no annotations provided, the description carries the full burden of disclosing behavior. It only states the generic capability without explaining how build vs parse is selected, whether existing query parameters are preserved, or what happens on invalid URLs. This lack of behavioral detail is a meaningful gap for a dual-purpose 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 a single, focused sentence that directly states the tool's purpose. Every word earns its place, and there is no fluff or redundancy. It is as concise as possible while still being informative.

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 tool has a dual-action capability (build and parse) but the description and schema do not clarify how the tool distinguishes between these modes or what the output format is. There is no annotation or output schema to compensate. The schema explains inputs well, but the overall context remains incomplete for understanding the tool's full behavior and edge cases.

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 schema covers 100% of parameters with individual descriptions, so the baseline is 3. The tool description adds no extra semantic meaning beyond what the schema already provides; it simply reiterates 'campaign tracking URLs.' Therefore, the description does not enhance parameter understanding beyond the structured input.

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 'Build and parse campaign tracking URLs' uses specific verbs (build, parse) and a specific resource (campaign tracking URLs). It clearly distinguishes this from sibling URL tools like url-encoder or url-shortener by focusing on UTM campaign tracking. The title 'UTM Builder' is fully expanded with actionable detail.

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 implies usage for constructing or dissecting UTM-tagged URLs but provides no explicit guidance on when to choose this tool over alternatives. It does not state exclusions, prerequisites, or compare against sibling tools like url-shortener. A minimally viable user would understand the general context, but clear when-to-use instructions are absent.

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