get_day_pillars

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It does disclose that only year, month, and day pillars are returned (and never an hour pillar), which is a meaningful constraint. However, it says nothing about side effects, return format, or error behavior, though for a simple query tool this may be sufficient.

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, informative sentence that front-loads the main purpose. Every word earns its place, and there is zero redundancy or filler.

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's simplicity (2 params, no output schema), the description provides a clear statement of what is returned. However, the complete lack of parameter semantics makes it less than fully self-sufficient. It is adequate but with a clear gap in parameter documentation.

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 two parameters (date, timezone) with no descriptions, and schema description coverage is 0%. The description does not compensate by explaining what these parameters mean, their format, or how timezone affects the result. This leaves the agent without any guidance on how to fill the parameters.

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 a specific verb ('Return') and resource ('date-level year, month and day pillars'), explicitly excluding hour pillars. This distinguishes it from sibling tools like get_four_pillars, which likely includes the hour pillar.

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 implied usage is that this tool is for retrieving date-level pillars, but there is no explicit guidance on when to use it versus alternatives or when not to use it. The 'never an hour pillar' clause hints at a distinction but does not name alternatives.

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