list_databases

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

The description adds meaningful behavioral context beyond the readOnlyHint annotation by stating it reads only the server's policy configuration, does not connect to any database, and never returns credentials. This reassures the agent about safety, side effects, and sensitive data exposure.

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 three sentences, each earning its place: what the tool returns, how the output connects to other tools, and what the tool does not do. It is front-loaded with the core purpose and contains no filler.

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 zero parameters, an output schema, and readOnlyHint annotations, the description is complete enough for an agent to call the tool correctly. It explains the output's role, the access mode/policy state, and the safety profile without needing to duplicate structured schema data.

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, so there is no parameter meaning for the description to add. The baseline of 4 is appropriate because no parameter documentation is needed and the description focuses on the valuable output semantics instead.

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 and resource: it lists databases the server is configured to query, along with tables, access mode, and policy enforcement state. It also distinguishes itself from sibling tools by clarifying these are database aliases usable as the 'database' parameter for other tools, not schemas, objects, or query execution.

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 for use by noting every returned alias can be passed as the 'database' parameter of other tools. It does not explicitly name sibling alternatives or include when-not-to-use conditions, so it stops short of full routing guidance.

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