compare_sites

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

With no annotations, the description discloses key behaviors: concurrent audits, return of screenshots and grade comparison table, and that it is free. However, it does not state if the tool is read-only, mention potential performance impacts, or describe error conditions. More context on side effects would improve transparency.

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 short paragraphs with no redundant information. The first paragraph immediately states the tool's purpose and actions, and the second provides usage guidance and a note about cost. Every sentence adds value.

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 no output schema, the description adequately explains the output (screenshots and grade comparison table). It covers the main inputs, actions, and outputs. It could benefit from more detail on the output format or error handling, but it is sufficiently complete for an agent to understand the tool's role.

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 clear descriptions for each parameter. The description adds minimal extra meaning beyond the schema; it reiterates the URLs and their purpose (first and second URL to audit). Baseline of 3 is appropriate given sufficient schema coverage.

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 performs competitive benchmarking by auditing two URLs side-by-side and producing a comparison report card. It explicitly lists the audit types (accessibility, performance, SEO) and differentiates from sibling tools like 'compare_screenshots' and individual audit tools.

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 explicit use cases: 'benchmark their site against a competitor, compare staging vs production, or evaluate two different sites.' It implies when to use this comprehensive tool over single-audit tools, but does not include explicit negative guidance or alternatives.

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