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

Annotations already declare readOnly=true and destructiveHint=false. The description adds meaningful behavioral context beyond annotations, including the business permission check, FREE-business restriction, the requirement to call check_business_tool_access, and the need to display warnings and block when access is denied.

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 each sentence earns its place. The first sentence states the action, and the rest delivers critical preconditions without unnecessary 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?

Given the tool's complexity (11 params, nested objects, no output schema), the description covers access prerequisites well but leaves filter semantics, pagination, and return shape undocumented. It is minimally viable but not fully complete for autonomous invocation.

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 only 9% with 11 parameters, so the description needs to compensate. It only vaguely refers to 'bucket and member filters' (bucketName and filters), leaving role, status, sortBy, pageSize, etc. unexplained. This is insufficient to clarify the many under-specified parameters.

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 ('Search') and resource ('recipients for a Magic Reach message') with a filtering mechanism ('bucket and member filters'), clearly indicating the tool's function. However, it does not explicitly contrast this with adjacent siblings like list_magic_reach_message_recipients, so it slightly misses the top score.

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 explicit usage prerequisites: check business permissions before offering, FREE businesses cannot use, call check_business_tool_access, show grace-period warnings, and never proceed when access is blocked. This is strong when-to-use guidance, though alternatives are not named.

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