create_recipient

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

With no annotations provided, the description carries the disclosure burden and does meaningful work: it reveals non-unique emails, non-idempotent creation, and account scoping. It could also mention response shape or auth requirements, but the core side effects are clearly disclosed.

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 description is two sentences with no filler. The main purpose is front-loaded, and the critical reuse warning immediately follows, making the behavior easy for an agent to parse quickly.

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 create operation, the description covers purpose, account scope, and the non-idempotency warning. Since there is no output schema, it could explicitly state that the response contains the new recipientId, so a small gap remains.

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 100%, so the schema already documents all three parameters well. The description adds context about non-unique emails and recipientId, but does not add new per-parameter meaning beyond what the schema supplies.

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 states a specific verb ('Store') and resource ('a recipient') and explains why it exists: so envelopes can reference recipients by recipientId. It also distinguishes the tool from reuse-oriented flows by noting each call creates a new recipient.

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 explicitly tells the agent to use list_recipients first when reuse is intended, and warns that emails are not unique. It does not explicitly contrast create_recipient with update_recipient, but the guidance for the main alternative is concrete and actionable.

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