credential_history

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: secret values are hidden, i.e. the agent should not expect retrievable plaintext. It does not describe ordering or volume of returned versions.

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?

One sentence, front-loaded with the resource and scope, with the parenthetical caveat placed immediately after the noun it qualifies. Nothing 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?

For a simple read-only lookup with no output schema, the description covers what is returned (previous versions, redacted values) and why it exists. The main gap is the opaque 'ref' parameter, but the retrieval semantics and safety posture are otherwise adequately conveyed.

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?

There is one parameter, 'ref', with 0% schema description coverage, so the description must carry the semantic burden. It only implies that ref points at a credential via the phrase "a credential's secrets" and gives no format, identifier type, or example, leaving the single required parameter effectively undocumented.

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 a specific resource (a credential's secrets) and specifies that it returns previous versions, which clearly separates it from get_credential (current values). It does not explicitly name or contrast with siblings like rollback_credential or audit_log, so it stays just short of 5.

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?

"for auditing / rollback" implies the workflow contexts in which this tool is used, giving more than nothing. But it never says when to prefer this over get_credential, rollback_credential, or audit_log, so the guidance remains implied rather than explicit.

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