list_periods

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

With no annotations, the description carries the full burden. It adds useful context by specifying that periods can be years, semesters, quarters, or months, but does not disclose other behaviors such as how missing variables are handled, whether domain affects results, or whether the operation is read-only (though 'list' implies so).

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 purpose and adds value by enumerating possible period types. It is front-loaded and contains no wasted words.

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 listing tool with two optional parameters and no output schema, the description provides sufficient context: it names the resource (periods), ties it to a variable, and explains the possible period granularity. However, it omits details about the domain parameter's role and any output structure, but these are not critical for a straightforward list operation.

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 both parameters (var and domain). The description adds no new parameter semantics beyond reinforcing that periods are tied to a variable; it does not elaborate on the domain parameter or provide format details beyond the schema.

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 lists available data periods for a given variable, with a specific verb (list) and resource (periods). It identifies common period types (years, semesters, quarters, months), but does not explicitly distinguish itself from sibling tool list_derived_periods, so it lacks full sibling differentiation.

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?

There is no guidance on when to use this tool versus alternatives like list_derived_periods, nor any exclusions or prerequisites beyond implying a variable is needed. The description says 'for a given variable' but does not explain when one would choose this over other list tools.

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