discover_tools

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

Annotations already declare readOnly, openWorld, and idempotent hints. The description adds valuable context about behavior beyond those: it returns matches with parameters, enabling invocation via execute_tool, and it surfaces 'specialist tools that are not advertised in tools/list.' This clarifies the operational scope without contradicting the 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?

The description is two sentences, front-loaded with the core action, and includes all essential information (what it searches, what it returns, and when to use it). No wasted words.

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 meta-tool that searches a catalog, the description fully covers the agent's needs: it states what the tool does, what it returns ('each match with its parameters'), and when to invoke it. With no output schema, the return value description is sufficient for the agent to decide to use execute_tool afterward.

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%, and parameter descriptions in the schema already explain query, showSchema, and includeExposed. The tool description adds no additional parameter-level detail beyond what the schema provides, so it 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 clearly states the tool's function: 'Search the full tool catalog, including specialist tools that are not advertised in tools/list.' It uses a specific verb ('Search') and resource ('tool catalog'), and distinguishes itself from sibling tools by highlighting its role as a discovery mechanism for unlisted tools, which is unique among the provided siblings.

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 gives explicit guidance: 'Call this when none of the listed tools fits.' This directly tells the agent when to use it, and implies that it is the fallback for unlisted capabilities. It also references tools/list and execute_tool, providing clear context for workflow integration.

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