list_roles

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

The readOnlyHint annotation already tells the agent this is a safe read, so the '[READ]' prefix is largely redundant. The description does add value by naming the attributes exposed (superuser/login/replication), but it omits any hint about privileges needed to enumerate roles or the shape of the result.

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?

Very short and front-loaded: purpose first, then a compact Args block. The bracketed '[READ]' tag is mildly redundant with the annotation but costs almost nothing.

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 single-optional-parameter, read-only listing tool with no output schema, the description covers purpose and parameter semantics adequately. Only the absence of return-format or privilege context keeps it from being fully complete.

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 coverage is 0% and the schema only declares an anyOf string/null with default null, so the description carries the burden. It does so well: 'target: Target name from config; omit for the default' explains both the meaning and the default behavior of the sole parameter.

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 and resource ('list' + 'roles') and even enumerates the attribute types returned (superuser/login/replication). No sibling tool overlaps with role listing, so no differentiation is needed; the '[READ]' tag is decorative but the core statement is clear.

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 never says when to use this tool versus alternatives, nor does it give conditions or exclusions. The only usage-like hint is the parameter note 'omit for the default', which is about the argument, not tool selection.

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