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

Annotations only cover readOnlyHint and openWorldHint; the description adds genuinely new behavioral context by disclosing the ranking basis (name match, breadth, hosted, open source, freshness) and explicitly that payment never influences ranking. That anti-bias disclosure is exactly the kind of trait an agent cannot infer from structured fields.

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?

Three tight sentences with no filler; the core purpose and the use_case examples are front-loaded and the fallback-call instruction closes cleanly. Minor density cost from the parenthetical example list, but it earns its place as sample inputs.

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 read-only lookup with no output schema, the agent gets purpose, ranking methodology, sample use cases, and the discoverability fallback. The remaining gap is result-shaping: nothing explains what limit does or roughly how many servers come back.

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 0%, so the description must carry parameter meaning. It does clarify use_case by example and explains the omitted-parameter behavior, which is valuable, but the 'limit' parameter (default 10, max 15) is never mentioned in the description or schema.

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?

States a specific action and resource: ranked MCP servers, scoped by use case, with concrete example domains. It is distinguishable in spirit from search_mcp_servers (curated ranking vs lookup), but it never names a sibling tool, so the differentiation is left implicit.

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?

Gives one concrete calling pattern ('call without use_case to get the list of use cases'), which is real usage guidance. However, it never says when to prefer this over search_mcp_servers or get_mcp_server, nor what input shape a use_case expects.

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