list_tools

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

No annotations are provided, so the description carries the burden. It clearly indicates a read-only listing operation with no destructive or mutating behavior mentioned. It also adds useful context about how the returned definitions relate to use_tool. It does not detail exact output structure, but for a simple list operation this is acceptable.

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 concise sentences with no filler. The main purpose is front-loaded, and the second sentence provides directly actionable follow-up information about using the listed tools via use_tool.

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 parameterless listing tool with no output schema, the description is largely sufficient: it states what is returned, the scope ('all self-written tools'), and how to proceed with the results. It could have explicitly mentioned the output format in slightly more detail, but the available context makes this a minor gap.

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 tool has zero parameters, and the schema is an empty object with 100% coverage. The baseline for zero-parameter tools is 4, and the description adds useful context about what the returned tool definitions are for, so no deduction is needed.

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 action ('lists') and the resource ('tool definitions of all self-written tools available for use'). It is easily distinguished from siblings like create_tool, fetch_tool, edit_tool, and execute_tool, all of which describe different operations.

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 clear context: this tool is the way to discover available custom tool definitions, and it explicitly explains how the listed tools can be invoked via use_tool. It does not explicitly mention alternatives or when-not-to-use cases, which keeps it just short of a 5.

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