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

Annotations already carry readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds the fact that the registry covers approved APIs, MCP servers, and CLIs)Skiping, which is useful but not deeply behavioral. It does not disclose pagination or result ordering behavior.

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?

A single, focused sentence that front-loads the primary action (Search), the resource, and the filtering method. There is no filler or repeated schema 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?

For a simple read-only search tool with three optional parameters and no output schema, the description is reasonably complete. It does not describe the return shape or pagination, but given the registry-search context and annotations, the missing detail is unlikely to cause incorrect 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 documents query and category with useful descriptions, and limit has default/min/max constraints. The description loosely maps to query and category but adds no parameter-level detail beyond the schema. With 67% schema coverage, the description does not fully compensate, but the missing param semantics are low-risk.

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 a specific verb ('Search'), a precise resource ('Agent Nexus registry of approved APIs, MCP servers and CLIs'), and the mechanism ('by keyword and optional category'). This clearly separates it from sibling tools like list_categories, get_entry, and discover_capabilities.

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 conveys clear context for a keyword-driven registry lookup, but it does not explicitly say when this tool should be preferred over the sibling tools or when not to use it. The intended use is implied rather than stated.

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