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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral context: the check is conditional on permissions, free business restrictions, and the need to call another tool first. It does not contradict 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 front-loaded with the purpose and includes necessary usage instructions. It is reasonably concise, though the multiple sentences about permissions could be slightly more compact. 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?

Given the simple nature of the tool (2 parameters, no output schema, annotations present), the description covers the check logic, prerequisites, and restrictions. It does not specify the return type (likely boolean), but that is implied. Fairly complete for a read-only check.

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%, so the description must compensate. It explains the 'lastObjectId' parameter as 'after an object ID', adding meaning. However, it does not describe the 'communityId' parameter in detail, nor the format or nullability of 'lastObjectId'. This is adequate but minimal.

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 tool's purpose: checking for unread chat messages after an object ID. It also clarifies that 'business' and 'community' are interchangeable. However, it does not explicitly differentiate from siblings like 'has_unread_community_chat' or 'has_new_unread_business_chat', which could cause confusion in selection.

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 guidelines: check business permissions, note that FREE businesses cannot use this tool, and call check_business_tool_access before collecting inputs. It also instructs to show grace-period warnings and never proceed when access is blocked. This is comprehensive and actionable.

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