compare_urls

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

Without annotations, the description carries the burden. It discloses that it returns scores and check results, implying a non-destructive read operation. However, it does not mention network access, potential failures, or what 'agent readiness' entails. Adds some context but not rich behavioral detail.

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 sentences, front-loaded with the action, and contains no unnecessary words. Every phrase adds value: the range, the purpose, and the output.

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 simple one-parameter schema and no output schema, the description adequately explains the return value ('scores and check results for each URL'). It could mention prerequisites like URL accessibility, but for a straightforward comparison tool, it is largely complete.

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 a clear description for the 'urls' parameter (2 to 4 URLs). The tool description adds only 'side by side' which is more about behavior than parameter semantics. Baseline 3 is appropriate since the schema already fully documents the parameter.

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 verb 'Compare' with a specific resource ('2–4 websites') and purpose ('for agent readiness'). It distinguishes from sibling tools by emphasizing 'side by side' comparison, which sets it apart from single audits or leaderboards.

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 provides clear context: this tool is for comparing 2–4 websites simultaneously. It does not explicitly name alternatives or when-not-to-use, but the 'side by side' wording implies it is for multi-URL comparison rather than single audits, which is sufficient guidance.

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