create_draft_reply

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

No annotations are provided, so the description carries full behavioral burden. It implies the result is a draft rather than a sent message (useful), but says nothing about required permissions, whether it appends to or overwrites an existing draft, which folder it lands in, or what happens on an invalid thread_id.

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 efficient sentence with the verb and scope front-loaded and no filler. It is well sized for what it attempts, though brevity here comes partly from omission rather than precision.

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 write/create tool with no annotations, no output schema, and 0% parameter coverage, the description should disclose far more. It gives no auth requirements, no draft-lifecycle behavior, and no return information, so an agent cannot call it confidently.

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 0%, so the description needed to compensate and does not. It never explains thread_id (format/lookup source) or reply_text (plain text vs markdown, length limits), leaving both required parameters undocumented in both schema and description.

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+resource ('Creates a draft reply') and a scope ('for a specific thread'), so the agent knows exactly what the tool produces. It does not explicitly contrast with the sibling get_unread_emails, but the read/write distinction is clear from the verb.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as sending a reply directly versus drafting one. The agent is left to infer that this is the compose-not-send path.

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