Credential Expiry

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

Annotations (readOnlyHint, idempotentHint) already indicate safe read behavior. The description adds important context: it never returns secret values, and it specifically handles control-plane secrets. This goes beyond annotations by clarifying what is NOT exposed.

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: first states the primary purpose concisely, second adds detail without redundancy. Every sentence adds value, and the description is well front-loaded.

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?

Despite having no parameters and an output schema, the description fully explains the tool's purpose, scope (control-plane secrets), and what it does not return. It is complete for an agent to understand its capabilities.

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?

With zero parameters, the schema coverage is 100%. The description appropriately has no need to explain parameters. Baseline score of 4 for no-parameter tools is met.

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 clearly states it returns expiring/overdue credential posture for control-plane secrets, specifying details like near expiry, overdue for rotation, and an overall verdict. This distinctively differentiates it from sibling tools which cover other security and compliance functions.

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 implies usage when credential expiry status is needed, but lacks explicit guidance on when to use this tool over alternatives (e.g., access_review, audit_query). No exclusions or context about when not to use it are provided.

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