slack_dm_history

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

No annotations are provided, so the description carries the burden. The verb 'Read' implies a non-mutating operation, and the parameter descriptions add some semantic context (e.g., 'Resolve user IDs to display names'). However, there is no disclosure of potential side effects, permissions, rate limits, or pagination behavior. This is adequate but not rich.

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 concise, front-loaded with the purpose, and uses a clean Args format. Every sentence adds value with no redundancy or fluff.

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?

An output schema exists, so return values need not be explained. Parameters and purpose are well covered. The only gap is the lack of guidance on when to use this versus sibling tools, but overall the description is complete enough for a read-only DM history tool.

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 0%, but the description thoroughly defines all four parameters: user (username, @username, or ID), limit (default 50), oldest (date or epoch), and resolve_names (boolean effect). This fully compensates for the missing schema descriptions.

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 uses a specific verb and resource: 'Read direct-message history with one person.' This clearly distinguishes it from sibling tools like slack_channel_history (channel history) and slack_thread (threads), making the tool's purpose unambiguous.

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 tool's context is clear: it is for direct-message history with a single user. However, it does not explicitly state when not to use it or mention alternatives from the sibling list (e.g., slack_search), so it lacks explicit exclusions.

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