messages_read

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context about the return format (raw vs. fenced content) and a security warning about untrusted Discord data, which goes beyond the 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?

The description is well-structured with clear sections (Purpose, When to use, Example, Returns, Security). Every sentence provides distinct value, and it is compact without padding.

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-only list tool with an output schema and rich annotations, the description covers all necessary context: purpose, use cases, example invocation, return shape, and a security note. Nothing essential 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 coverage is 100% and each parameter already has a description (e.g., 'Get messages after this ID (newer)'). The description's example ({channel_id, limit:50}) adds a concrete usage illustration but does not explain any parameter semantics beyond what the schema already provides.

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 'Read recent messages from a Discord channel' – a specific verb, resource, and scope. It also mentions two concrete use cases (catching up and locating a specific message), which differentiates it from siblings like messages_get and messages_search_recent.

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 two clear scenarios: catching up on a channel and locating a specific message by content/author. However, it does not explicitly state when not to use this tool or name alternative tools, so it stops short of a perfect 5.

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