mess_get_preferences

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds value by specifying the return structure (JSON UserPreferences with specific fields) and authentication requirements (auth_key or session). It doesn't mention rate limits, error conditions, or data freshness, but provides useful context beyond 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 reasonably concise but has structural issues. The first sentence is clear, but the Args/Returns formatting is inconsistent with typical MCP descriptions. The return field listing is helpful but could be more efficiently integrated. Some redundancy exists between 'Get all user preferences' and the return description.

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 tool has comprehensive annotations (readOnly, non-destructive, idempotent, openWorld) and an output schema (implied by Returns section), the description provides adequate context. It covers authentication needs and return structure. For a simple read operation with good annotations, this is reasonably complete, though could benefit from error handling or usage scenario details.

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 mentions 'params: auth_key or session' which maps to the single parameter's structure. However, it doesn't explain the relationship between auth_key and session (mutually exclusive? both required?), nor does it clarify what happens if neither is provided. The schema's AuthInput definition provides more detail than the 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 'Get' and resource 'all user preferences', making the purpose explicit. It distinguishes from sibling 'mess_update_preferences' by being a read operation. However, it doesn't specify whose preferences (current user vs others) or differentiate from other get_* tools that might return user data.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (authentication state), compare with 'mess_get_me' or 'mess_get_info' which might include preference data, or indicate when this specific tool is needed versus general user info tools.

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