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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds meaningful context beyond that: the exact fields returned and the explicit 'No credentials' guarantee, plus the underlying GET endpoint. It omits pagination behavior, which the schema covers anyway.

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?

Three telegraphic clauses with zero padding: what is returned, what is excluded, and the endpoint. Front-loaded with the resource, no sentence is wasted.

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?

There is no output schema, so the description's field enumeration (id, name, collation) usefully compensates. Combined with schema-documented pagination and read-only annotations, an agent has what it needs; only the relationship to sibling list tools is unstated.

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?

Schema description coverage is 100%, so all three parameters (page, per_page, server_id) are already documented in the schema, including paging semantics. 'On a server' restates the server_id requirement but adds no format or constraint detail, so the baseline of 3 applies.

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 names the resource (databases on a server) and enumerates the returned fields (id, name, collation), which combined with the title 'List databases' gives an unambiguous read-only list operation. It does not explicitly distinguish itself from the closest sibling runcloud_list_database_users, though 'No credentials' hints at the boundary.

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?

There is no explicit when-to-use or when-not-to-use guidance, but the 'No credentials' qualifier implicitly routes an agent looking for DB usernames/passwords to runcloud_list_database_users instead. Usage is inferable rather than stated.

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