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

With no annotations provided, the description carries the burden of explaining behavior, and it does enumerate the returned chart components in reasonable breadth. However, it doesn't disclose whether this is a pure read-only computation, whether it imposes timezone/location constraints, or what happens when required inputs are missing.

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?

A single, information-dense sentence with no filler. The main subject and scope are front-loaded, and the enumerated contents flow naturally.

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?

For a tool with no output schema and no annotations, the description gives a broad content summary but lacks return format details and explicit edge-case behavior. It is adequate for a high-level selection, but an agent inferring the exact JSON shape or error semantics would need more information.

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 the baseline is 3; the description only adds semantic value by summarizing those inputs as 'date, time and place'. It does not clarify deeper parameter interactions like house_system defaults or how tz_offset_minutes affects computations, leaving that to 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 states exactly what resource the tool produces—a 'full birth chart'—and enumerates its contents: planetary positions, house cusps, aspects with orbs, element/modality balance, and configurations. This clearly distinguishes it from narrower siblings like planet_positions or moon_state.

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 word 'full' plus the enumerated contents implies this tool is for complete natal chart data, but the description never explicitly says when to choose this over alternatives like planet_positions or aspect_exact_time. There is a clear implied usage, but no explicit when-not guidance or sibling references.

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