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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It reveals that the tool returns either targetUrl or disabledReason, that it does not count as a scan, and that it only handles the '_' class codes. This gives the agent a clear picture of side effects and outcomes.

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 three sentences, dense and free of fluff. Every sentence adds relevant detail: purpose, accepted input forms, return behavior, scan-count caveat, and code-class restriction.

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 one-parameter tool with no annotations and no output schema, the description is fully sufficient. It explains the operation, input normalization, output possibilities, and exclusions, leaving no significant gaps for the agent to guess.

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 coverage is 100% for the single 'code' parameter, so the baseline is 3. The description adds value by showing accepted input variants (alias, with slash, or full URL) and reinforces the '_' class restriction, which helps clarify normalization beyond the schema's examples.

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 verb and resource: 'Resolve a scanned qart.uk code to the URL it currently points at.' It distinguishes itself from sibling tools by explicitly scoping to the '_' code class and excluding older link shapes.

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 gives clear when-to-use and when-not-to-use guidance: it applies to '_' codes only, not older qart.uk links. It also notes that resolution does not count as a scan, which is useful context, though it does not explicitly name an alternative tool.

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