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

Annotations establish the operation as read-only and non-destructive. The description adds valuable behavioral context beyond annotations by stating it is synchronous, blocks until completion or timeout, and returns specific fields (risk score, confidence, agent access guidance, intent_alignment). It does not cover all edge cases like timeout behavior or error responses, but with annotations this is sufficient.

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 two concise sentences. The first sentence states the core action, synchronous behavior, and return fields; the second clearly pivots to the async alternative. Every word earns its place with no redundancy or fluff.

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?

Given the tool is a single URL scanner with two parameters, no output schema, and no nested objects, the description is complete. It covers the synchronous behavior, names the return fields, and directs users to the async flow for long-running scans. The annotations and schema fill in the remaining safety and parameter details.

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% with both parameters described (url and intent), so the schema does the heavy lifting. The description adds a general mention of 'optional user intent context' but does not provide additional parameter-specific meaning beyond what the schema already conveys. Baseline of 3 is appropriate per the rubric.

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 the tool analyzes a URL for security threats with optional user intent, using a specific verb and resource. It distinguishes itself from the async variant by explicitly noting it is synchronous and blocks until completion or timeout, and from the non-intent sibling by mentioning the optional intent context.

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 explicit guidance on when to use this tool versus the async alternative: 'For long-running scans, prefer url_scanner_async_scan_with_intent which returns immediately with a task_id for polling via url_scanner_async_task_result.' This clearly directs the user to the appropriate tool based on scan duration.

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