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

With no annotations provided, the description carries the transparency burden. It notably discloses that any install_hint is a best-effort guess, not a verified command, and instructs the agent to relay the caveat rather than presenting it as ready to run. This is valuable behavioral context beyond the 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?

Two sentences with no filler. The core purpose is front-loaded, and the critical install_hint caveat is placed immediately after, earning its place as essential guidance.

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 a simple one-parameter lookup and the description covers what the entry includes plus the important caveat. It does not mention error behavior for unknown ids, but for this low-complexity tool the provided information is sufficient for correct invocation.

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 schema already fully documents the 'id' parameter with 100% coverage. The description adds an explicit format ('owner--repo') and a concrete example, which reinforces the schema but does not substantially expand semantics beyond 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 names the specific action ('Get the full directory entry for one MCP server by id'), identifies the resource type, and even specifies the id format with an example. It clearly differentiates this from sibling tools by focusing on a single server lookup rather than searching or listing.

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 conveys that this tool is for retrieving one server by exact id, which implies it should be used when you already know the owner--repo identifier. It does not explicitly name alternatives, but the id-based scoping is clear enough to guide selection.

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