gmail_cancel_scheduled

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

No annotations are provided, so the description carries the full burden. It does disclose the key behavioral fact for a mutation: the message is not sent and reverts to a draft. It omits the index/query selection model, whether the cancel can be undone, and any auth or permission requirements, leaving real gaps for a state-changing tool.

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 no filler. The outcome (not sent, becomes draft) is the first thing stated, followed by the useful pointer to gmail.drafts.

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?

Given three params, no output schema, and no annotations, the description explains the essential effect but not how the index/query pair selects a message or what the agent gets back. Adequate for a simple cancel action but not fully self-sufficient.

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%, with all three parameters documented in-schema including the default for index and the purpose of expect_subject. The description adds no further parameter detail, which is acceptable at full coverage but earns only the baseline.

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?

Names a specific verb and resource ('Cancel a scheduled send') and states the resulting state ('becomes a draft again'), which distinguishes it from gmail_send and gmail_discard. It stops short of contrasting itself with gmail_scheduled by name, relying on a parenthetical reference instead.

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 through the schema's references to 'Row index from gmail.scheduled' and the '(see gmail.drafts)' pointer. There is no explicit statement of when to reach for this versus gmail_scheduled (listing) or gmail_delete_draft (removal), so the agent must infer the workflow.

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