Mark Email Answered

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

Annotations indicate non-read-only, non-destructive, idempotent. Description adds that 'answered' defaults to true, explains the folder-scoping issue with IMAP UIDs, and warns that moving to the same folder is a no-op. This adds significant behavioral context beyond annotations.

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?

Two sentences: first states purpose, second gives key usage guidance. Extremely concise, front-loaded, with no wasted words.

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 simple flag-setting tool with output schema and annotations, the description covers the main functionality and the critical sourceFolder nuance. Lacking explicit mention of return values, but output schema likely covers that. Nearly 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 description coverage is 33% (only sourceFolder has a detailed description). The tool description adds the default for 'answered' and briefly reiterates sourceFolder guidance, but does not describe 'emailId', which is required and lacks schema description. Parameter semantics are only partially enhanced.

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 ('Set or clear') and the resource ('the \Answered flag on an email'), and distinguishes it from sibling tools like mark_email_read or mark_forwarded by specifying the IMAP flag.

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?

Provides explicit guidance on when to pass 'sourceFolder' (when UID came from a folder other than INBOX) and warns against using 'All Mail'. However, it does not explicitly contrast with alternatives like mark_forwarded, leaving when to use this vs other flag tools somewhat implied.

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