mark_read

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

No annotations are provided, so the description carries full burden. It discloses that the tool sets the IMAP Seen flag (a write operation), but does not mention any prerequisites, permissions, or side effects (e.g., triggering notifications). This is adequate but not thorough.

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 minimal and front-loaded with the main action, followed by a clear 'Args:' section. Every sentence serves a purpose 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?

Given the simple operation and presence of an output schema (for return values), the description covers the essential inputs and behavior. It does not detail return structure, but that is handled by the output schema. Minor improvement could include noting the effect on message state.

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 0%, but the description explains that 'message_ids' are IMAP sequence numbers and 'folder' is the IMAP folder with a default of INBOX. This adds meaning beyond the schema's title and type, compensating well for lack of schema 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?

The description clearly states the verb 'mark' and the resource 'messages as read', explicitly linking to IMAP Seen flag. It is specific and distinguishable from siblings like 'read_message' (which reads content) and 'move_message'.

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 directly states the action and the default folder (INBOX), implying its typical use. It does not explicitly mention when not to use it or list alternatives, but the purpose is sufficiently clear for an agent to decide.

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