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

The description adds a behavioral detail beyond the annotations: labels are created if they don't already exist. While the annotations already indicate the tool is not read-only, this note clarifies a side effect but does not cover other aspects like error handling or idempotency.

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 a single, concise sentence that immediately states the action and the key side effect. It is well-structured with no redundant or extraneous information, making it easy to parse.

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?

The description covers the primary action and a notable side effect, but it omits details about the return value or any error conditions. Since no output schema is provided, the agent is left without knowledge of what the tool returns, which is a gap for a complete understanding.

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?

The schema describes queue_id and case_id, but the labels parameter lacks a description. The tool description does not compensate, offering no explanation of what 'labels' entails beyond its name. This leaves ambiguity for the labels structure, especially since it contains nested key-value pairs.

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 action: 'Assign one or more labels to a case' and adds a specific side effect about creating missing labels. It distinctively describes the tool's function without ambiguity, and the name aligns well with the description.

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 does not provide explicit guidance on when to use this tool versus alternatives like unlinkCaseLabels or updateCase. It merely states what the tool does, leaving the agent to infer the appropriate context from the tool name and sibling list.

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