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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real behavioral value beyond them: compact results, featured-first then most-viewed ordering, and the returned fields (slug and mcp.tc link).

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 sentences, zero waste, and the core purpose is front-loaded ahead of the sibling handoff and the no-args case. Each sentence carries distinct information.

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?

Despite an output schema existing, the description still summarizes result shape and ordering, and it covers the empty-argument case and the follow-up tool. Nothing needed to invoke or chain this tool is missing.

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 all four parameters including the enums and limit bounds are fully documented in the schema. The description only gestures at the same axes ('keyword, category or how they connect') without adding format or syntax beyond what the schema already provides, so the baseline 3 applies.

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 verb and resource ('Search the mcp.tc directory of MCP servers') and qualifies the search axes (keyword, category, connection type). It is immediately distinguishable from get_server (detail lookup) and list_categories.

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?

Explicitly routes the agent onward: 'Call get_server with a slug for the endpoint URL, install command and setup steps,' and explains the no-argument behavior. It gives clear usage context but does not say when to prefer list_categories instead.

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