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 behavioral disclosure. It mentions 'absolute and % deltas' and keyword support, but does not detail side effects, output format, or whether it is read-only. This is moderate transparency for a comparison tool.

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 two sentences, front-loaded with the action and result, and contains no unnecessary words. It is efficient and clearly communicates the tool's purpose.

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 has 5 parameters, no output schema, and no annotations, the description is moderately complete. It explains the core functionality but lacks detail on output format, filter behavior, or how the deltas are presented. For a tool of this complexity, it is adequate but not comprehensive.

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 baseline is 3. The description adds that 'Both periods accept the same friendly keywords as date_range', but this is already detailed in the parameter descriptions. It does not provide additional meaning beyond what the schema already conveys.

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 compares aggregate metrics between two periods with absolute and % deltas, and gives concrete examples like 'yesterday vs the day before', distinguishing it from siblings like get_stats (single period) and get_timeseries (time series).

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 use cases (e.g., 'yesterday vs the day before', 'this week vs last week', before/after a deploy) and notes that both periods accept friendly keywords, which guides the agent on when to use. It does not explicitly mention when not to use or alternatives, but the context of sibling tools is available.

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