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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful orchestration context — that the result feeds vault_id into other tools — but says nothing about pagination, ordering, or what an empty result means; minor for a zero-param list tool.

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?

Three short sentences, each doing distinct work: what it returns, when to call it, and what happens if you skip it. The sequencing instruction is front-loaded in sentence two.

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?

An output schema exists, so return values needn't be fully enumerated, and the annotations cover safety. For a zero-param read tool, the description supplies exactly the missing piece — when to call it and the downstream dependency — and nothing else.

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 doesn't invent parameter meaning where none exists, and correctly frames the output values as the inputs other tools require.

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 your vaults') and names the returned fields (IDs, names, slugs), which no sibling tool does. An agent can immediately distinguish this from list_folder, list_tags, or list_fields.

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?

Explicit trigger: 'Call this first when you own more than one vault,' plus the cross-tool dependency that every vault-scoped tool needs a vault_id. It also names the alternative behavior ('search_notes without one searches all vaults'), leaving nothing to inference.

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