list_databases

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

With no annotations, the description carries the full burden; it does disclose a meaningful trait — that no credentials are returned — plus the 'availability' dimension, which hints results may be filtered by availability. It says nothing about permissions required, ordering, pagination, or whether unavailable databases are omitted vs flagged.

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?

A single tight sentence with the resource front-loaded and the security-relevant caveat ('no credentials') appended. No filler and nothing redundant.

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?

A simple, parameterless read tool with an output schema that covers the return shape; the description adds the useful 'availability' and 'no credentials' framing. What remains missing — result ordering and handling of unavailable databases — is minor given the output schema exists.

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?

Zero parameters, so baseline 4 applies. There is nothing parameter-wise for the description to compensate for, and the schema is trivially complete.

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?

States a specific verb+resource ('List configured database identifiers') and enumerates the returned fields (identifiers, descriptions, availability). It implicitly separates itself from sibling list_tables by naming database-level rather than table-level resources, though it never names the alternative outright.

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?

Usage is only implied: an agent can infer this is the discovery entry point before list_tables/get_schema, but the description never says when to prefer it or what it excludes. No explicit when/when-not guidance or named alternatives.

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