list_derived_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 only states the operation ('List derived periods') without mentioning return format, pagination, authentication needs, error behavior, or whether the listing is derived dynamically. This is a significant gap for a tool with zero annotation coverage.

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, front-loaded sentence that efficiently communicates the core purpose with no wasted words. It is appropriately sized for a tool of this simplicity.

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?

For a simple 2-parameter tool with no output schema and no annotations, this description is minimally viable but leaves gaps. It does not state what the response contains, explain the role of the domain parameter, or mention any default behavior. Given the low complexity, some additional context would improve completeness, but the current text is adequate at a basic level.

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 input schema already describes both parameters (var as 'Variable ID' and domain as 'BPS domain code') with 100% coverage. The description adds no additional meaning beyond the schema, so the baseline of 3 is appropriate. It neither enhances nor contradicts the schema's parameter documentation.

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 uses a specific verb ('List'), resource ('derived periods'), and scope ('for a given variable'), clearly distinguishing it from sibling tools like list_periods (which lists all periods) and list_derived_variables (which lists variables, not periods). This is a precise and unambiguous statement of the tool's function.

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 offers no guidance on when to use this tool versus alternatives such as list_periods or list_derived_variables. It does not mention prerequisites, exclusions, or selection criteria beyond the trivial fact that it applies to a given variable, leaving the agent without useful decision-making information.

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