email_send_html

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

With no annotations, the description carries the full burden. It discloses key behavioral traits: the email is composed via clipboard injection into Mail.app's rich-text compose window and sent immediately, plus the outbound allowlist policy. This goes beyond typical stub descriptions and provides operational context an agent needs.

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 concise sentences with no redundant wording. The main action is front-loaded, followed by critical behavioral notes and policy constraints. Every sentence earns its place.

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?

The description covers essential operational details: direct send, clipboard injection mechanism, immediate sending, and allowlist policy. It omits failure handling or return details, but an output schema exists, so return behavior need not be in the description. For a mutation tool with no annotations, this is reasonably 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 coverage is 100%, so all parameters are already described in the input schema. The description does not add parameter-specific details beyond the schema; it only reiterates that the body must be an HTML string, which is already in the schema. Baseline of 3 is appropriate.

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: 'Send an HTML email directly.' It further clarifies 'Does not save a draft first,' which distinguishes it from draft-related siblings like draft_send and draft_create. The scope is clear and unambiguous.

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?

The description explains the primary use case (direct send without draft) and implies this is the go-to for immediate sending. However, it does not explicitly name alternatives or state when not to use it, such as 'use draft_send to send an existing draft.' The context is useful but not fully explicit.

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