unlock_vault

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

Annotations establish the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the burden is reduced. The description still adds genuinely non-obvious behavior: unlocking triggers a user-facing dialog and the passphrase never flows through the agent, which changes how an agent should sequence and narrate the call. It stops short of covering cancel/failure behavior or whether the call blocks.

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, zero padding, action front-loaded with the security mechanism in parentheses. 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?

For a zero-parameter tool with annotations covering the safety profile and no output schema, the description supplies what matters most (mechanism and secret handling). Minor gap: no mention of what the agent/user sees on success, cancel, or a wrong passphrase.

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 zero parameters (schema coverage 100%), so there is no parameter semantics to explain and the baseline of 4 applies. The description correctly implies the passphrase is deliberately not an agent-supplied argument.

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?

Specific verb ('Unlock') plus resource ('the vault'), and the description goes further by naming the mechanism (a secure passphrase dialog). It is unambiguously distinct from the sibling lock_vault and from read-only tools like vault_status.

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?

Usage is only implied: an agent can infer this is the action for a locked vault, but the description never states when to call it versus alternatives (e.g., checking vault_status first) or what happens if the vault is already unlocked. Adequate but leaves the routing decision to inference.

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