compare_engines

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

No annotations are provided, so the description carries the burden, but it is minimal. It doesn't disclose that this likely performs multiple searches, how it handles provider failures, or that it returns a merged result set. The 'max_total_results' parameter hints at merging but not explicitly in the description.

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 concise sentence that front-loads the core purpose. No fluff, but lacks detail that could be added without verbosity.

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 likely complex (comparison, multiple providers, merging results) and has no output schema or annotations, the description is thin. It doesn't explain the return shape, how to select providers, or what happens with zero providers. The complexity warrants more detail.

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%, so the schema already documents all parameters clearly. The description adds no additional semantic value beyond what the schema provides, such as examples or the meaning of comparing providers. Baseline 3 is appropriate.

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 states a clear verb ('compare') and resource ('providers'), and specifies the action ('side by side for the same query'). It distinguishes from sibling search tools by focusing on comparison rather than a single search, though it doesn't explicitly name alternatives.

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 when comparing providers for a query, but does not explicitly state when to use this tool versus just using a single search tool like search_web or when not to use it. The parameter descriptions add some context ('Empty = all enabled') but not explicit routing guidance.

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