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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is clear. The description adds useful algorithmic context about how the 24 planetary hours are derived and links to a full output and error contract, though it does not discuss auth or rate limits because none are relevant for this public read-only tool.

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 front-loaded with the core purpose, then organized into WORKFLOW, INPUT CONTRACT, and DO NOT CONFUSE WITH sections. Every sentence carries distinct information, and the external documentation link is appropriately placed at the end for deeper contracts.

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 complexity and the presence of an output schema, the description covers what is computed, when to use it, what input structure is expected, and how it differs from sibling tools. An agent has everything needed to select and invoke it correctly without opening the schema.

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 nested location schema already documents date, lat, lon, timezone, and response_format. The description reinforces the input contract by listing the same fields and the YYYY-MM-DD date format, but adds no meaningful syntax or constraint beyond what the schema provides.

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?

States a specific verb and resource ('The 24 planetary hours for a date and place') and explains the calculation in enough detail to distinguish it from generic time tools. It explicitly names the sibling tools it must not be confused with, asterwise_get_hora and asterwise_get_choghadiya, and gives their differentiating features.

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?

Provides a WORKFLOW section stating the tool is standalone and should be followed by asterwise_get_western_void_of_course_moon. The DO NOT CONFUSE WITH section names two alternatives and explains the exact difference, leaving no inference required about when to choose this tool.

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