discord_get_message_attachments

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

Beyond the readOnlyHint annotation, the description adds important behavioral context: CDN URLs expire after 24 hours and are not re-signed, so the agent must re-call the tool if a stored URL has expired. This is exactly the kind of non-obvious behavior an agent needs to know.

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 front-loaded with the core purpose and then provides necessary behavioral details. The return-field list is a bit long but each item gives useful semantic information, and the URL-expiry and permission notes justify their space.

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 an output schema present, the description does not need to enumerate return values, yet it does anyway for clarity. It covers permissions, URL expiry, read-only behavior, and the sibling tool to use for finding messages, making it fully actionable.

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 schema already fully documents channel_id and message_id. The description does not add much parameter-specific meaning beyond what the schema provides, so the baseline of 3 is appropriate.

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 states a specific verb ('List') and resource ('file attachments of a message'), making the tool's function unambiguous. It clearly distinguishes itself from sibling tools like discord_read_messages by focusing on attachment retrieval rather than message content.

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 explicitly tells the agent to use discord_read_messages to find messages with attachments, providing a clear alternative and routing condition. It also states required permissions (View Channel, Read Message History), giving necessary usage context.

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