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

Annotations already establish that this is a read-only, open-world operation. The description adds that results include node counts and that the tool is intended for initial discovery, but it does not describe return format, pagination, or any other behavioral details beyond that.

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 front-loaded with the core action and usage guidance in the first two sentences. The third sentence adds registry scale and domain examples that are somewhat promotional but still provide relevant context for understanding what the pillar list covers.

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 zero-parameter, read-only listing tool without an output schema, the description gives enough context to understand what is returned: pillars with node counts. It does not fully specify the exact response shape, but the essential invocation context is present.

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 an empty input schema, so there is no parameter semantics for the description to explain. The baseline score of 4 applies because there are no parameters that require clarification.

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 a specific verb and resource: listing compliance pillars in the Bidda registry with node counts. It implies differentiation from search-oriented siblings by saying to use it before searching, but it does not explicitly name an alternative tool.

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 phrase 'Use this first to discover available compliance domains before searching' gives clear guidance on when to call this tool. It lacks explicit when-not conditions or named alternative tools, so it is strong but not fully complete.

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