Western Secondary Progressions

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

The description does not add behavioral traits beyond the annotations. The annotations already declare readOnlyHint: true, idempotentHint: true, and destructiveHint: false, and the description is consistent with these. It explains the computational method but that is functional, not behavioral (e.g., side effects, rate limits). Since the annotations already cover safety aspects, the description adds no extra behavioral context, hence a neutral score.

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) and contains useful disambiguation. However, some redundancy exists: the 'DO NOT CONFUSE WITH' section repeats the same contrast twice (e.g., 'uniform arc vs individual motion' and 'real-time sky, not symbolic progression'). Overall it is concise and informative, but slightly repetitive.

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 description provides rich context: the exact formula (1 ephemeris day = 1 tropical year = 365.2421904 days), the workflow sequence, and clear differentiation from related tools. It also mentions the output content (progressed planets, Ascendant, MC, solar arc). This gives the agent a complete understanding of the tool's purpose and relationship to siblings.

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 schema provides 100% coverage of parameters with detailed descriptions (e.g., birth object fields, target_date, response_format). The description text repeats the same information (e.g., 'target_date (optional YYYY-MM-DD) — the date to progress to. Defaults to today.') without adding new semantic detail. Thus it meets the baseline for complete schema coverage but adds no extra value.

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 it is a 'Secondary progressed chart using the day-for-a-year method' and explicitly lists what it returns: '10 progressed planet positions, progressed Ascendant and MC, and the solar arc.' This leaves no ambiguity about the tool's function.

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 via the 'WORKFLOW' section (BEFORE: asterwise_get_western_natal, AFTER: asterwise_get_western_solar_arc) and the 'DO NOT CONFUSE WITH' section, which distinguishes it from solar arc (uniform motion) and transits (real-time sky). This is excellent usage direction.

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