reply

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

The description adds some behavioral context beyond annotations by revealing that the tool is a wrapper over create_draft with seed=reply, clarifying that it creates drafts/reply flow. Annotations already declare readOnly=false and destructive=false, but the description doesn't go into side effects such as immediate sending or reply-all behavior.

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 two short sentences with no filler. It front-loads the core action and then gives a functional relationship to create_draft.

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?

With a rich parameter schema and an output schema, the description covers the essential behavior and wraps semantics. It misses an explicit distinction from reply_all and its exact sending/draft behavior, though the schema defaults cover the latter.

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 baseline is 3 and the description doesn't need to restate parameter meanings. The 'seed=reply' detail gives useful conceptual context, but it doesn't add meaning beyond the schema for individual parameters.

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 names the operation with a specific verb and resource ('Reply to an existing message') and reveals its implementation path as a wrapper over create_draft with seed=reply. It does not explicitly differentiate from reply_all or forward, but the 'existing message' target makes the scope reasonably clear.

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 phrase 'Convenience wrapper over create_draft with seed=reply' implies a targeted alternative to create_draft, but there is no explicit statement of when to choose this over reply_all or when a fuller create_draft call is preferable. Usage guidance is present only by implication.

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