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

With no annotations, the description carries the burden. It discloses ordering ('Ordered by creation date descending') and return field compatibility ('same security/risk/pricing fields as search_servers'), which helps set expectations. It does not mention rate limits or pagination behavior, but for a simple read-only list tool this is sufficient.

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 primary purpose, followed by usage guidance and behavioral details. No wasted words—every clause adds useful context.

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 straightforward list tool with fully described params and no output schema, the description covers core behavior: ordering, optional time filters, and the fact that results include security/risk/pricing fields (referencing search_servers). It lacks a full return-shape declaration, but the sibling reference helps fill that gap.

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 coverage is 100%, so all three parameters (days, limit, free_only) have descriptions in the schema. The tool description adds minimal extra meaning beyond restating the optional date constraint ('Optionally constrain to the last N days'). This meets the baseline but does not exceed it.

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 opens with 'List the most recently added MCP servers', giving a specific verb, resource, and scope. It explicitly differentiates from siblings by framing this as a discovery tool for 'what's new', 'latest servers', 'servers from this week', which is distinct from search_servers or get_server.

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 clearly states when to use it: 'Use for discovery: what's new, latest servers, servers from this week.' It also mentions optional date constraint. However, it does not explicitly name alternatives or say when NOT to use it, though the sibling reference to search_servers provides indirect comparison.

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