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

Annotations already mark the tool as read-only, idempotent, and non-destructive, so the description adds value by revealing the archive size, the nature of results (free previews and purchase URLs), and the payment implication. This goes beyond what annotations provide, though it does not detail behaviors like pagination or sorting.

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 core action, and every sentence adds substantive information. It avoids redundancy with the schema and annotations, making it highly efficient and well-structured.

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 presence of an output schema, the description does not need to explain return values in detail. It adequately covers the tool's purpose, result type, and usage guidance, and is complete enough for a search tool with two parameters. A slight gap is the lack of explicit comparison to the sibling archive_catalog, but this is likely covered by the sibling tool's own description.

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?

The input schema already provides thorough descriptions for both parameters (query with example, limit with meaning), yielding 100% schema coverage. The tool description adds context about using concise Spanish terms and the relationship between previews and payment, enriching the meaning of the parameters beyond the schema fields.

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's function with a specific verb ('Search') and resource (the Comrades of War archive), and distinguishes it from the sibling archive_catalog by emphasizing search over browsing. It also specifies the content type and the result format (free previews and purchase URLs), making its purpose unambiguous.

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 guidance on how to use the tool: it instructs using concise Spanish terms and notes to pay only when a preview is relevant. It does not explicitly mention when to use this tool instead of archive_catalog, but the search-focused nature implicitly differentiates it, so the context is clear though not exhaustive.

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