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

Annotations already declare readOnlyHint=true, so the description does not need to state safety. It adds the comparison dimensions but does not disclose any other behavioral traits such as output format, error handling, or identifier validation. This is acceptable given the annotation but adds limited extra 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 a single, front-loaded sentence with no redundant words. It efficiently communicates the action and scope.

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?

For a simple comparison tool with one array parameter and a read-only annotation, the description covers what is compared and the input constraint. It does not explain the return format, but the lack of an output schema means the description carries some responsibility; however, the listed comparison facets imply a side-by-side result, which is adequate. The description is complete for the tool's moderate complexity.

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 description coverage is 100% with a clear description of 'identifiers' as canonical server identifiers in namespace/name format. The tool description only adds that these are MCP servers and the 'up to four' constraint, which is already encoded in schema maxItems. No significant additional meaning is provided.

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 uses a specific verb 'Compare' with the resource 'MCP servers' and explicitly lists the comparison dimensions (score, verdict, auth, tool count, prompts/resources, freshness), clearly distinguishing it from siblings like search_servers or get_server_report.

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 use for comparing multiple servers side by side but provides no explicit when-to-use or when-not-to-use guidance, nor does it name alternatives. The usage context is inferred from the verb 'Compare' rather than stated.

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