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

With no annotations supplied, the description carries the full burden and does a solid job: it establishes an authenticated context, characterizes the result as masked/grouped metadata, and makes a strong guarantee that decrypted values are never returned. It does not discuss rate limits or pagination, but for a read-only summary the key behavioral traits are disclosed.

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 short sentences front-load the primary purpose and add only one high-value constraint. Every word contributes; there is no redundant restatement of the title or schema.

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 lightweight optional-parameter summary tool with an output schema, the description covers the core return behavior and safety guarantee. It is less complete on parameter semantics and sibling differentiation, so an agent may still need to infer the meaning of limit and include_fields before invoking.

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?

Input schema description coverage is 0%, yet the description never mentions what limit or include_fields control. The names and constraints (integer 1-200, boolean default true) provide some self-evident meaning, and include_fields can be loosely tied to 'masked field previews,' but the agent is left to guess the precise effect of each parameter.

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 verb and resource: 'Return profile metadata, grouped field counts, and masked field previews for the authenticated Vault.' The 'summary' focus and 'masked' language distinguish it from sibling Vault tools like vault_documents and vault_field_write even without naming them.

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 intended use is implied by the stated outputs, and 'Decrypted values are never returned' gives a clear negative signal for anyone needing raw secrets. However, it never explicitly says when to prefer this over sibling tools such as vault_documents or vault_fill, nor does it name alternatives or prerequisites.

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