gmail_reply

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

Annotations only declare readOnlyHint=false, destructiveHint=false, openWorldHint=true. The description adds genuinely useful behavior: the send is immediate and irreversible (no draft stage) and quoting is applied to the output. It does not mention auth requirements or rate limits, but the immediate-send disclosure is the single most important trait for this 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?

Three short sentences, zero filler, with the consequential 'sends immediately' fact front-loaded in the first sentence where an agent will see it while deciding whether to call the tool.

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?

No output schema exists, so the description would ideally hint at what comes back (e.g. sent message id), and it says nothing about the html parameter. It does, however, cover the send semantics, reply_all, and quoting behavior, which is enough for correct invocation in most cases.

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 50%: id and attachments are documented, but body, html, reply_all, and quote_original are bare. The description compensates for reply_all ('also replies to everyone on To/Cc') and quote_original ('original text is quoted below your reply', matching the default-true schema note), but leaves html and body unexplained. Partial compensation lands at a 3.

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 (reply) and resource (email in its thread) plus the key scope qualifier '(sends immediately)'. This implicitly separates it from gmail_create_draft and gmail_send_email, though it never names those siblings explicitly, so it falls short of 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?

The parenthetical 'sends immediately' hints that this bypasses drafting, and the reply_all sentence gives context for that flag, but there is no explicit when-to-use/when-not guidance versus gmail_send_email, gmail_forward, or gmail_create_draft, which are live alternatives in the sibling list.

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