describe_tools

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=false. The description adds 'No network call. Read-only, safe to retry.' and describes the return format in detail. This provides additional behavioral context beyond annotations, but annotations already cover the core safety profile.

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 well-structured: first sentence states the main purpose, second provides usage guidance, third mentions alternative, fourth describes behavior, and fifth outlines the return format. Every sentence adds value, and it is front-loaded with the primary action.

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?

The description is complete for a tool with zero parameters and explicit annotations. It explains the risk tiers, return format, and safe behavior. Given the tool's simplicity and the presence of annotations and output schema, no additional information is necessary.

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?

With 0 parameters and 100% schema coverage (empty schema), the description adds meaning by explaining the purpose and return structure. Baseline is 4 for no params, and the description provides sufficient context.

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 that the tool lists every tool with machine-readable risk classification for policy enforcement. It uses a specific verb ('List') and resource ('every tool'), and distinguishes itself from sibling tools by being a meta-tool that provides risk metadata.

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 states when to use the tool: 'before granting access or building automation.' It also mentions an alternative: 'A runtime-security gateway can also read the same signal from the MCP tool annotations ... via tools/list.' This provides clear when-to-use and alternative guidance.

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