mdb_list_databases

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

With no annotations, the description carries the full burden of behavioral disclosure. It helpfully describes the returned content (config labels, session status, connection instructions), but does not explicitly state that the operation is read-only, whether it has side effects, or what happens on failure, leaving gaps in the 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?

Two sentences with zero waste, and the critical directive 'ALWAYS call this first' is front-loaded before the return details. 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?

Given the zero-parameter schema, no annotations, and no output schema, the description is nearly complete: it establishes the call order, the data source, and the returned artifacts. It stops short of describing error behavior or how to interpret the connection instructions, but those are minor gaps for a discovery tool.

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 takes zero parameters, so the baseline is 4 per the scoring rules. The description adds no parameter information because none is needed, and the empty schema fully covers the input contract.

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 (returns) and enumerates the exact resources returned: configured database labels from config.json, active dynamic session status, and connection instructions. It also positions the tool as the bootstrap step, which clearly distinguishes it from sibling tools like mdb_connect or mdb_query.

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 instruction 'ALWAYS call this first to discover how to connect' gives explicit when-to-use guidance and establishes the tool as a prerequisite. However, it does not name alternative tools or state when not to use this tool, leaving some routing inference to the agent.

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