draft_reply

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

No annotations are provided, so the description carries the behavioral disclosure burden. It explains the analysis behavior (thread history, style matching, commitment tracking) which is helpful context. However, it doesn't disclose side effects like whether create_draft actually saves, where drafts are stored, or whether the tool needs specific auth/permissions.

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 concise (two short paragraphs) and front-loaded with the core purpose. The bullet-like second paragraph adds meaningful differentiators without padding. Slightly verbose in the multi-line formatting but otherwise well-structured.

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 drafting tool with an output schema available and 100% parameter coverage, the description covers the key aspects: what it does, how it behaves (context awareness, style matching), and what it considers (commitments). It could add more on side effects and return behavior, but the existing annotations coverage makes this reasonably complete.

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 100%, so the schema already explains all 4 parameters thoroughly. The description adds context about the tool's behavior but doesn't elaborate on parameter usage beyond what schema descriptions provide. Baseline 3 is appropriate since the schema handles the parameter documentation.

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 clearly states the verb+resource ('Draft a reply to an email thread') and highlights its differentiators: context awareness, thread analysis, writing style matching, and open commitment/delegation consideration. This effectively distinguishes it from sibling drafting tools like create_email_draft, draft_email, and draft_follow_up.

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 explains what makes this tool special (context awareness, style matching, commitment consideration), which helps an agent choose it over create_email_draft or draft_email. However, it doesn't explicitly state when NOT to use it or name alternatives like draft_email for the simplest cases.

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