Send email

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the agent knows this is a non-destructive but externally-visible action; the description is consistent with that. It adds the useful context that the outbound artifact is a 2FA setup code (so re-invocations resend rather than create state), but says nothing about delivery side effects, rate limiting, or whether an existing setup session is required.

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 short sentence, front-loaded with the verb and the target, with no filler. Its brevity is efficient but comes at the cost of the missing guidance noted in the other dimensions.

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 an outbound side-effecting tool with 0% parameter documentation, no output schema, and several similarly named email siblings, the definition leaves too much unspecified. The agent cannot determine argument shape or how this differs from vaultwarden_send_email_login without inspecting the schema or guessing.

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% and the three parameters (form, params, json_body) are generic pass-through containers with null defaults. The description mentions no parameters at all, so an agent has no guidance on what to place in these fields or whether calling with no arguments is the intended usage.

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+resource ("Send/resend ... verification code") and narrows it to the email-2FA setup flow, so an agent knows it is not a generic email sender. It does not name or differentiate against close siblings such as vaultwarden_send_email_login or vaultwarden_post_email, which is the only thing keeping it from a 5.

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?

Usage is only implied by the phrase "email-2FA setup verification code" — an agent can infer it belongs in the two-factor enrollment flow. There is no explicit when-to-use/when-not, no mention of the near-duplicate vaultwarden_send_email_login alternative, and no statement of prerequisites (e.g., a pending 2FA setup session).

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