vault_deposit

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

With no annotations, the description carries the full burden and does so richly: encryption at rest, that other agents use the key without seeing it, the auth encoding formats, the risk enum's behavioral consequence ('high: every write asks the user'), and the deferred-send semantics of base_urls. This is exactly the behavioral context annotations would otherwise supply.

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?

The purpose leads the paragraph, then parameter guidance follows in a logical order. It is dense and parenthetical-heavy, but for a 13-parameter tool most sentences earn their place; a few could be broken into clearer structure.

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 13-param mutation tool with no annotations and no output schema, the description covers purpose, usage, permissions, and most parameters. Remaining gaps are minor parameter definitions (agent, api_key, extra_headers) and any indication of what a successful deposit returns, but the agent has enough to call it correctly.

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% across 13 params, so the description must compensate, and it explains the non-obvious ones well: purpose, scope (with provider-level examples), used_in (with a concrete object shape), base_urls, auth (with the full bearer|basic|header|query grammar), and risk. It omits meaning for agent, api_key, extra_headers and description, which is the only reason this isn't a 5.

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+resource ('Hand over an API key, token or password ... so Commons keeps it (encrypted)') and immediately distinguishes the resource from its sibling by naming use_credential as the consumption path. An agent knows this is the deposit side of a credential store without opening the schema.

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?

Explicitly instructs when to act ('Deposit it the moment you get it') and routes to alternatives for deferred work ('or add them later with vault_note', 'until vault_hosts sets them the key is never sent anywhere'). It also states the permission boundary ('You can add new keys and update your own, not replace another's'), so the agent knows when this tool will and won't work.

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