calculate_aspects

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

With annotations already marking the tool readOnly, idempotent, and non-destructive, the description adds valuable behavioral context: results are factual and uninterpreted, and calculations follow GetBirthChart's methodology. It does not contradict annotations, though it leaves edge cases like unknown_time behavior to the schema.

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?

Two concise sentences, with the action and resource front-loaded. The second sentence only adds the important no-interpretation boundary. No filler, no repetition of schema content.

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 plus annotations and output schema cover the core contract for a read-only calculation tool. What is missing is explicit routing to sibling tools and clarification of how unknown_time affects aspect output; the schema hints at it but the description does not tie the calculation methodology to that input.

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 description offers no parameter-level guidance. Schema descriptions cover date, time, place, timezone, and unknown_time, but latitude and longitude are undocumented, and the description does not compensate for that gap or clarify the role of each input in aspect calculation.

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 identifies a specific verb ('Calculate'), a precise resource ('structured natal aspects between chart bodies'), and an output boundary ('Returns factual aspect data without interpretation'). This distinguishes it from sibling tools such as get_big_three or calculate_synastry without needing to open 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 use case is clearly implied: use it when you need calculated natal aspects. However, the description does not explicitly say when not to use it or direct the agent to a sibling such as calculate_birth_chart for a full chart, so routing between tools is left to inference.

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