search_tools

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context: it searches 500+ tools, returns 'matching tool names + descriptions ranked by relevance,' and avoids loading every definition. It doesn't mention pagination or exact result format, but the core behavior is transparent and consistent with annotations.

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 with zero waste. The core action and purpose are front-loaded in the first sentence, the return value is stated, and the usage guidance is compact. Every sentence earns its place.

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 search/discovery tool with readOnlyHint and openWorldHint annotations, a 2-param schema with 100% coverage, and no output schema, the description is nearly complete. It explains what it searches, what it returns, and when to use it. The only minor gap is not describing the exact shape of the results (e.g., whether descriptions are truncated), but that is not critical for an agent deciding to call it.

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 the schema already documents both parameters (query and limit) with examples. The description adds the context that query matches against 'tool names and descriptions' and that limit controls 'Max results,' which slightly reinforces the schema. Baseline 3 is appropriate because the schema does the heavy lifting and the description adds only marginal semantic value.

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 states a specific verb ('Search'), a specific resource ('the full NowAIKit tool catalog'), and a clear purpose ('discover the right tool without loading every definition'). It also distinguishes itself from the 200+ sibling tools by being the meta-search tool that finds them, so an agent can tell it apart without opening schemas.

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 explicitly says 'Use this FIRST when you are unsure which tool to call' and mentions the MCP_TOOL_DISCOVERY=lean scenario where only a small core set plus this search is exposed. This gives clear when-to-use guidance and implies it is the alternative to loading every definition. It could name a specific sibling alternative, but as a meta-tool its alternative is 'loading every definition,' which it explicitly addresses.

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