messages_read

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

With readOnlyHint=true and destructiveHint=false already set, the description still adds substantial value: it discloses the human-readable fencing tags, notes that structuredContent remains raw Discord data, and explicitly warns that Discord-authored fields should be treated as untrusted. This goes well beyond the annotations and is highly relevant for safe agent 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 well-structured with clear sections: Purpose, When to use, Example, Returns, and Security. It is front-loaded with the most important information, every section earns its place, and the security note is concise but critical.

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 read tool with an output schema and strong annotations, the description covers purpose, usage scenarios, an example invocation, return shape, and safety considerations. Nothing essential for an agent to call it correctly or handle its output safely is missing.

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 parameters are already well documented. The description adds a concise example with channel_id and limit, reinforcing usage, but does not add meaning beyond the schema for after/before or limits. 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 and resource ('Read recent messages from a Discord channel') and gives concrete use cases. It does not explicitly name sibling tools like messages_get or messages_search_recent to differentiate, but the plural 'messages' and 'channel' scope make the core purpose 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 'When to use' section provides clear contexts: catching up on a channel or locating a message by content/author. It does not explicitly state when not to use this tool or mention alternative tools such as messages_search_recent, but the provided guidance is actionable and context-rich.

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