pit_fields

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

With no annotations, the description carries the full burden, and it discloses that the call takes no request or account (a pure zero-input metadata read) and previews the returned content structure. It does not mention auth requirements or whether the dictionary is versioned/cached, but for a static zero-parameter lookup the disclosure is reasonably complete.

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?

Two sentences, purpose front-loaded, and the second sentence preempts a plausible misuse. The phrasing 'It compares nothing; no account and no request' is terse to the point of being cryptic, costing a little on readability for an otherwise waste-free description.

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?

With no output schema, no annotations, and no parameters, the description must convey what comes back — and it does by listing the per-line-item fields (unit, period type, definition, formula). It stops short of describing the shape (flat list, keyed by line item) or how derived vs. instant/duration rows differ in practice.

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 tool has zero parameters, so the baseline is 4. The description reinforces this by stating there is 'no account and no request,' confirming the agent cannot scope the lookup — which is meaningful given that sibling tools do take account arguments.

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 names the resource precisely ('the data dictionary for point_in_time') and enumerates what each line item carries: unit, period type (instant/duration/derived), definition, and formula for derived figures. It explicitly distinguishes itself from the sibling point_in_time by stating 'It compares nothing; no account and no request,' so an agent can separate it from the comparison tool without opening a schema.

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?

'It compares nothing; no account and no request' functions as a negative-use signal, steering agents that want comparison data toward point_in_time. It gives clear context for when this metadata lookup applies, though it never names the alternative sibling explicitly, so routing is inferred rather than stated.

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