vault_status

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

With no annotations and no output schema, the description carries the full burden, and it does disclose the salient return contents, including the identity format and the fact that OS keychain unlock state is reported (a failure-relevant signal). It stops short of stating permissions/auth requirements or that it is strictly side-effect free.

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?

A single front-loaded sentence with the verb first and a dense enumeration of reported fields. Every clause adds information; nothing is padding or restated from the name.

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, no-annotation, no-output-schema tool, the description supplies the return-surface detail an agent needs to interpret the result. Minor gaps remain around read-only guarantees and whether an unauthenticated call returns an error versus a status payload.

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, so the baseline is 4. The description correctly focuses on what is returned rather than implying any input, and there are no parameters left 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?

States a specific verb ('Query') and resource ('active MCP vault connection status') and enumerates the fields reported (agt_<ulid> identity, keychain unlock state, permission scopes). This makes it clearly a read-only diagnostic, distinguishable in substance from vault_get_secret or vault_search, though it never names a sibling explicitly.

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 pre-flight check to run before vault operations, especially given the keychain-unlock-state mention. There is no explicit when-to-use, when-not-to-use, or routing to alternatives such as vault_ssh_agent_status.

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