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

Annotations already declare readOnlyHint=true, but the description adds meaningful behavioral context: it never returns secrets and requires activated credential management. This goes beyond the annotation and helps the agent set expectations and anticipate possible failure.

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 short sentences with no wasted words. The primary action and scope are front-loaded, and the behavioral qualifier and prerequisite follow directly. Every clause adds value.

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 zero-parameter tool with no output schema and a readOnly annotation, the description covers the essential aspects: what it lists, what it never returns, and the required precondition. An agent has enough information to decide whether and how to invoke it.

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 input schema has zero properties, so there are no parameter details to describe. Per the baseline for zero-parameter tools, a score of 4 is appropriate; the description does not need to compensate for missing schema info.

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 uses a specific verb and resource: 'List your credential metadata'. The qualifier 'never secrets' makes it unambiguous what is returned and distinguishes it from any secret-returning functionality. The scope ('your') 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 states a prerequisite ('Requires explicitly activated credential management'), giving context for when the tool can be used. However, it does not explicitly name alternatives or state when not to use this tool, so usage guidance is more implied than explicit.

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