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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly explains what the tool returns, the token-saving behavior of detail='compact' (~15k tokens), and what is dropped in compact mode. It doesn't mention error cases or edge conditions, but for a read-only chart calculator the disclosed behaviors are meaningful and adequate.

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, followed by return contents, parameter behavior, and next-step guidance. Every sentence adds practical value, no fluff or repetition. It remains compact despite conveying substantial usage context.

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 an output schema exists, the description does not need to detail return structure, and it still covers use cases, output contents, detail-mode behavior, token impact, and downstream alternatives. This is complete for an agent to select and invoke the tool appropriately.

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 coverage is 50%, and the description compensates by explaining the 'detail' parameter's effects and trade-offs. It also reinforces that the same birth data can be reused for transits. The 'data' subfields are mostly self-explanatory via defaults and range constraints, though the description does not add direct parameter-level details for them beyond the schema.

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 immediately states the tool's purpose: 'Use when you need the full natal chart for interpretation, comparison, or downstream transit/progression work.' It goes beyond the name by listing the exact output components (planets, houses, aspects, patterns, dignities, Big Three) and positions itself as the full-chart option versus sibling tools like planetary_positions or get_planet.

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 explicit when-to-use guidance ('when you need the full natal chart'), distinguishes between detail levels (compact for placements+angles, full for aspect-by-aspect narrative), and names alternatives for transits ('current_transits' or 'transit_search'). This gives the agent clear decision criteria for tool selection and parameter choice.

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