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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does well by explaining the embedding mechanism, sorting by cosine similarity (highest first), exclusion of the reference server, and the inclusion of security/risk/pricing fields in results. This gives the agent a solid understanding of expected behavior, though it omits edge cases like empty results or error handling.

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 well-structured and front-loaded with the core purpose in the first sentence. Subsequent sentences provide usage context, technical method, sorting order, and output field details—each sentence earns its place. It is appropriately sized for the tool's complexity, with no wasted words or repetition.

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 and no annotations, the description is reasonably complete. It explains what the tool returns (servers sorted by similarity), how results are computed (embeddings, cosine similarity), and key output fields for comparison. It could additionally specify the exact response format (e.g., list of server objects), but the description covers the most critical aspects thoroughly.

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%, so the baseline is 3. The description does not add extra meaning beyond the schema for each parameter; the schema already explains slug, limit, and free_only. However, the overall description provides context for how these parameters affect behavior (e.g., excluding the reference, limiting results), but this is not per-parameter added value.

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: "Find MCP servers that are semantically similar to a reference server." It uses a specific verb and resource, and distinguishes from sibling tools by focusing on semantic similarity rather than search or comparison. Examples like 'like this but safer' further clarify the intended use case.

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 explicitly says when to use: "Use when a user picked a candidate but wants alternatives." This provides clear context for invocation. It does not explicitly name alternative tools or state when not to use, but the 'Use when' instruction is strong enough to guide selection. The mention of search_servers in the output context also hints at a related tool.

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