get_session_roles

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

No annotations are supplied, so the description carries the full burden. It does disclose the returned fields (admin option, default-role flag) and a misuse warning, but never states that it is a side-effect-free read, nor any permission/connection prerequisites. That is a modest but real gap for a zero-annotation tool.

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, zero filler: the first front-loads what is returned, the second front-loads the calling condition and the prohibition. Every clause 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?

With no output schema, the description compensates by naming the returned attributes, and the usage constraints cover the main selection risk. The only shortfall is the absence of any behavioral note (read-only nature, connection prerequisite), which would matter more given the lack of annotations.

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 no parameters, so there is nothing for the description to disambiguate; the schema is trivially complete at 100% coverage. Baseline for zero parameters 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?

States a specific verb (List) and a precisely scoped resource (roles enabled for the current connection), plus the returned attributes (admin option, default-role flag). This clearly separates it from the nearby sibling get_session_privs, which deals with privileges rather than roles.

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?

Explicit when-to-call ('only when the user explicitly asks which roles the connection has') and an explicit exclusion ('do NOT call as a preamble before querying tables or objects'). Nothing about usage is left to inference.

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