list_servers

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

No annotations are provided, so the description carries the full burden. It discloses the return format ('Returns JSON') and the key fields (scanned_at, scan_age_days, stale flag, grade), giving the agent insight into what to expect. It does not mention side effects, but the verb 'List' implies a read-only operation, and the output description adds meaningful context beyond the empty input schema.

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 long and front-loaded with the main purpose. The second sentence adds specific output details without redundancy. No word is wasted, making it highly concise 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?

The tool is simple (no params, no annotations) and the description fully covers what the tool does and what it returns. The output schema exists, so the description doesn't need to exhaustively list return values, but it already provides key fields. For a list tool, this is complete enough for an agent to select and invoke it correctly.

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 tool has zero parameters, so the description does not need to explain parameter usage. The schema is empty and coverage is 100%, meeting the baseline for no-parameter tools. The description appropriately focuses on the output rather than inputs.

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 the specific verb 'List' and clearly identifies the resource: 'every graded MCP server.' It also states what the output contains (trust grade and scan freshness), distinguishing it from sibling tools like check_server (which likely checks a specific server) and get_methodology.

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 phrase 'List every' clearly indicates this is for retrieving an overview of all servers. It doesn't explicitly name alternatives or exclusions, but the scope is unambiguous. The context of siblings (check_server, get_methodology) implies usage, though no explicit when-to-use guidance is given.

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