calendar.macro_dday

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

With no annotations, the description carries the full behavioral burden and succeeds: it reveals the tool is static and pre-loaded for 2026, makes no live API call, cannot fail due to upstream outage, accepts no parameters, and specifies success/error return structures. This gives the agent realistic expectations about freshness and failure modes.

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 well-structured with a summary, usage guidance, exclusions, and return format. It loses a point for minor redundancy between 'takes no parameters' and 'Takes no arguments; calling it with any input is unnecessary,' but every other sentence carries useful information.

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 zero-parameter, read-only calendar tool, the description is complete: it states the data source, scope, update nature, use case, output fields, and failure format. Even without an output schema, the agent can predict what a successful call returns and how to interpret errors.

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 has no parameters, so the baseline is 4. The description reinforces this by stating twice that the tool takes no arguments and that any input is unnecessary, which removes any temptation to pass 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 opening line precisely describes the tool's output: a countdown to the nearest FOMC/CPI/NFP event with date/time, impact, and upcoming events. It also disambiguates by limiting coverage to US macro events and naming the exact event types tracked, so an agent won't mistake it for an earnings or non-US calendar.

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 explicitly tells the agent to use this for position sizing or holding risk planning before high-impact macro prints. It also states exclusions: non-US events and earnings are not covered, and only FOMC/CPI/NFP are tracked, making the appropriate use boundary clear.

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