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

Annotations already include readOnlyHint=true and idempotentHint=true, covering the key behavioral aspects. The description adds context about the output (tags each hour with ruler, quality, and 'current' status) and references a full output/error contract link. This goes slightly beyond the annotations, though it doesn't explicitly mention side effects or permissions (which are covered by the readOnlyHint).

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 clear sections (WORKFLOW, INPUT CONTRACT, DO NOT CONFUSE WITH, full contract link). It is concise yet comprehensive, using bullet-like separations to convey essential information without unnecessary verbosity, especially given the large number of sibling tools it must differentiate from.

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?

The tool has a relatively simple input structure (one nested location object) and an output schema is present. The description provides enough context to understand the tool's purpose and output, and it includes a link to the full output/error contract. Given the output schema exists, the description adequately covers what an agent needs to invoke it correctly.

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 100% description coverage for all properties, including date format, lat/lon ranges, timezone default, and response_format enum. The description only restates the location rules ('date/coordinate rules apply locally') without adding new semantic details beyond the schema, so it does not exceed the baseline for schema-covered 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 the specific function: 'Builds the twenty-four planetary Horas between successive sunrises for a location and tags each hour with ruler, quality text, and whether it is current.' It also explicitly differentiates from sibling tools like asterwise_get_choghadiya and asterwise_get_natal_chart, ensuring no ambiguity.

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 description provides explicit guidance on when to use this tool versus alternatives. It states 'WORKFLOW: BEFORE: None — this tool is standalone' and 'DO NOT CONFUSE WITH' sections that clarify the differences from get_choghadiya and get_natal_chart, giving clear conditions for selection.

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