list_recent_sends

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it states the timestamp is the send time and is stable across calls, which is important for pagination/consistency expectations. It also discloses the returned fields (send status, subject, recipient, timestamp, messageId) and the limit cap behavior. This is meaningful added context, though it doesn't discuss rate limits or error cases.

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 compact and front-loaded: the core purpose and ordering are in the first sentence, followed by the stable timestamp note, return fields, sibling pointer, and parameter clarification. Every sentence earns its place and there is no fluff or repetition of schema details.

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 read-only list tool with an output schema present, the description is quite complete. It covers what is returned, the ordering, the stability of the timestamp, and how to follow up for full delivery details. It doesn't mention pagination beyond the limit parameter, but the stable timestamp and limit cap give enough for an agent to call it correctly. The output schema likely covers return structure, so the description need not explain it further.

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 both parameters (limit and since) with descriptions. The description adds a bit of extra meaning by explaining the `since` parameter accepts a full ISO 8601 datetime string with an example, and by noting the default limit of 20 is in the schema. However, the schema already covers the semantics well, so the description's added value is marginal. Baseline 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?

The description states a specific verb ('List'), a specific resource ('recently sent emails from your Wraps email history'), and a clear ordering ('newest first'). It also names the sibling tool get_email_event_log for follow-up delivery details, which helps distinguish it from related tools. The scope is precise and an agent can tell it apart from send_email and get_email_event_log without opening schemas.

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 gives clear context for when to use this tool: to list recent sends and to obtain messageId for full delivery details via get_email_event_log. It does not explicitly state when not to use it or name alternatives for filtering/searching, but the sibling context and the explicit pointer to get_email_event_log provide adequate usage guidance. A small gap is that it doesn't mention that send_email is for creating sends, but that is fairly obvious from the sibling names.

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