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

Annotations already indicate readOnlyHint=true and destructiveHint=false. Description adds important context about business access restrictions and prerequisites, beyond what annotations convey. No contradiction.

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?

Multiple sentences, each serving a purpose: purpose, permission check, free restriction, prerequisite call, warning handling. Front-loaded with purpose, no 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?

Covers purpose, usage conditions, prerequisites well. However, lacks description of return value (no output schema) and error handling. Adequate but could be more complete given the tool's simplicity.

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 has 2 required string parameters (messageId, communityId) with 0% description coverage. Parameter names are self-explanatory, but description only says 'by id' without elaborating on which id or format. Could add more detail.

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 'Get one Magic Reach message by id', specifying the verb and resource. It distinguishes from sibling tools like list_magic_reach_messages and delete_magic_reach_message.

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?

Provides explicit instructions: check business permissions, free businesses cannot use, call check_business_tool_access first, handle warnings and resubscribe link, never proceed when blocked. This is comprehensive.

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