compare_periods

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It does not mention whether the operation is read-only, what the output looks like, how breakdown works, rate limits, or authentication needs. The only hint is that it 'compares performance,' which is too vague for a tool with 7 parameters.

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 with no wasted words. However, it is under-specified and lacks any structured breakdown of behavior or parameters. While conciseness is acceptable, the structure is minimal and does not earn the score higher than mid-range.

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 7 parameters, an output schema, and no annotations, this description is severely incomplete. It fails to explain the tool's purpose beyond a vague 'compare performance,' doesn't describe the period parameters, doesn't mention the breakdown option, and offers no context on when to use it. The tool needs much more elaboration to be usable.

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 43%, meaning only 3 of 7 parameters have descriptions in the schema. The tool description adds no information about any parameters, let alone the date ranges or breakdown field. It fails to compensate for the low schema coverage, leaving users without guidance on date formats, required fields, or how the breakdown parameter affects results.

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 function: comparing performance between two date ranges. It uses a specific verb ('compare') and resource ('performance'), and the comparison aspect distinguishes it from sibling tools that retrieve performance for a single period. However, it doesn't specify what kind of performance metrics or the output format, so it's not fully detailed.

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?

No explicit guidance is given about when to use this tool versus alternatives like get_campaign_performance or get_account_summary. The name and description imply its use for comparing two periods, but there are no stated exclusions, prerequisites, or alternative tool recommendations.

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