Accounts post prelogin

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

Annotations already declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds the login-context and the alternate mount path, but does not explain the mild tension between the retrieval wording ('Get') and the non-read-only annotation, nor return/pagination behavior. With annotations present, this adds modest value beyond structured data.

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?

A single front-loaded sentence with the purpose stated first and the mount alias in a compact parenthetical. Efficient with little waste, though the parenthetical is secondary detail that could be trimmed.

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 simple prelogin lookup with no output schema, the description conveys what is returned (KDF type/iterations) and its login context, which is the core need. However, with three undocumented body parameters and no guidance on how to supply the email, it is only adequately complete.

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 description coverage is 0% across three parameters (form, params, json_body), and the description does not compensate. It implies an 'email' input exists but never says which parameter carries it or what form/params mean, so there is little guidance beyond the bare opaque schema.

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 gives a specific verb and resource: 'Get KDF type/iterations for an email before login.' That is concrete enough for an agent to know it retrieves key-derivation config. It does not explicitly distinguish itself from the near-identical sibling vaultwarden_identity_post_prelogin, though the parenthetical about the alternate mount provides partial differentiation.

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?

'Before login' implies the timing context in which to use it, but the description never names or rules out alternatives such as vaultwarden_identity_post_prelogin or vaultwarden_prelogin_password. Usage is therefore implied rather than stated, leaving the agent to infer which prelogin tool to pick.

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