Performance By Device

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It does not state read-only/destructive status, authorization needs, rate limits, or that it returns aggregate reporting rather than modifying data; only the tool name implies a read operation.

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?

A single front-loaded sentence with no wasted words. It is extremely terse, but conciseness is appropriate and not verbose.

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?

An output schema exists and the input schema fully documents parameters, so the description need not explain return values or parameter details. It identifies the device breakdown clearly enough to route among the performance_by_* siblings, though it omits usage and behavioral context.

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 100%, so the schema already documents all five parameters including defaults and the search_type enum. The description adds device breakdown context but no parameter semantics beyond what the schema provides; baseline 3 applies.

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?

States a specific resource and breakdown dimension ('performance broken down by device'), and 'by device' distinguishes it from siblings like performance_by_date, performance_by_country, and performance_by_search_appearance. However, it lacks an explicit verb and does not directly name alternatives.

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 no when-to-use guidance, prerequisites, or comparison to alternative performance breakdown tools. The agent is not told when to choose this over performance_by_date, performance_by_country, or compare_periods.

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