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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the description's job is to add behavioral context — which it does: computation is bounded between successive sunrises, each hour is tagged, and a 'current' hour is identified. It also defers the full output/error contract to a docs URL. This meaningfully enriches what annotations provide without contradicting them.

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 core purpose is front-loaded in one dense sentence, followed by clearly labeled sections (WORKFLOW, INPUT CONTRACT, DO NOT CONFUSE WITH) and a docs link. Every component earns its place — there is no filler or repetition of annotation data, and the labeled structure makes the content skimmable for an agent.

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 nested LocationInput schema, an existing output schema, and a large sibling family, the description covers everything needed to call correctly: purpose, output characteristics, workflow position, input rules, disambiguation from the two most confusable siblings, and a reference to the full output/error contract. No material gap remains for an agent selecting or invoking this tool.

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 every parameter (date, lat, lon, timezone, response_format) is already documented in the schema. The INPUT CONTRACT line restates YYYY-MM-DD and bounded lat/lon, which adds little beyond schema constraints, though it usefully signals that a shared LocationInput contract applies. This meets the baseline for high schema coverage but adds no substantial new parameter meaning.

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 first sentence names a specific verb ('Builds'), a concrete resource ('the twenty-four planetary Horas between successive sunrises'), and the output shape (each hour tagged with ruler, quality text, and current status). The 'DO NOT CONFUSE WITH' section then explicitly separates it from asterwise_get_choghadiya and asterwise_get_natal_chart, so an agent can distinguish it from siblings without opening their schemas.

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 is unusually explicit: WORKFLOW states there is no prerequisite ('BEFORE: None') and names the natural follow-up (choghadiya), while 'DO NOT CONFUSE WITH' gives the disambiguating conditions — sixteen segments vs twenty-four Horas, and natal analysis vs hourly muhurta tables. An agent is told both when to use this tool and when not to.

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