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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by enumerating the concrete contents of the response and by implying the authentication requirement ('Authenticated workspace identity'), which the annotations do not express.

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 tight sentences, front-loaded with the core payload and followed by a single actionable routing cue. Every clause earns its place with no padding or repetition of the title.

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?

With no output schema, the description must carry the return-value burden, and it does so by naming the data categories returned. 'Health' is left somewhat vague as to what conditions constitute unhealthy, which is the only real gap for a zero-param, read-only diagnostic tool.

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 there is nothing for the description to disambiguate beyond what the empty schema shows. Baseline of 4 applies; no parameter-level semantics are missing.

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 resource and what it returns: authenticated workspace identity plus vault counts and health broken down by notes/sources/projects/last sync. It is clearly distinguishable from the list_* siblings because it is an aggregate status rather than an enumeration, though it does not name those siblings as contrasts.

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 implied (orientation/health check) rather than stated. The one explicit guidance sentence — a non-zero `projects` means list_projects has scopes worth searching — routes the agent to a downstream tool but does not say when to call vault_status itself or when to prefer it over list_notes/list_projects directly.

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