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

With no annotations at all, the description carries the full burden, and it does disclose two non-obvious traits: results are cursor-paginated, and returned fields named *_untrusted/Commons content must be treated as data rather than instructions. It stops short of stating that this is a non-mutating read, key ordering, or default page size, so it is strong but not complete.

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 sentences, purpose front-loaded, pagination and the safety constraint following in order of importance. The security sentence is long but it is load-bearing given the absence of annotations; nothing is obviously padded.

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 4-parameter tool with no annotations, no output schema, and zero schema descriptions, the definition covers purpose, filters, pagination, and content-safety but omits return shape, ordering, limit defaults, and multi-tag semantics. Adequate to invoke, not sufficient to invoke correctly in edge cases.

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?

Schema coverage is 0%, so the description must compensate; it names prefix, tag, and cursor, which is partial compensation for 4 parameters. It never explains that tag is an array (are multiple tags ANDed or ORed?), nor gives any hint of the limit bounds (max 200) or a default page size, leaving real ambiguity in both structured and unstructured text.

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 and resource ('List my current vault keys') plus the two filter dimensions and pagination, so an agent knows exactly what it enumerates. It does not, however, differentiate itself from close siblings like memory_search or vault_head, which could plausibly be mistaken for the same enumeration.

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?

Phrasing like 'by prefix or tag' implies the enumeration use case, and the untrusted-content warning implies when to be cautious with results. There is no explicit when-to-use/when-not guidance and no routing to memory_search or memory_get for content-based retrieval, so the agent must infer the boundary.

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