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

Goes well beyond the readOnly/idempotent annotations by disclosing determinism, that no LLM is called, credit cost with a free sandbox key, and the layer-status model (present/computed_empty/not_covered/failed). This tells the agent exactly what behavior and safety profile to expect.

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?

Front-loaded with the usage trigger, then behavior, cost, determinism (stated twice near-verbatim) and an example. The determinism restatement is redundant, but the structure is otherwise efficient and scannable.

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?

With an output schema present, return values need no explanation; the description still covers cost, determinism, layer-status reporting, and the alternative tool. Nothing needed to invoke it correctly is missing.

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 already 100% and the enum documents all 15 domains, so baseline is 3. The description adds value with a concrete example-arguments payload showing the exact birthData/domain shape, though it doesn't add semantics the schema lacks.

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?

States a specific verb+resource (a deterministic reading of one life area) and enumerates the domains covered. It explicitly contrasts itself with the sibling get_forecast, so an agent can route without opening either schema.

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?

Opens with a concrete trigger (user asks what their chart says about one life area and wants a reproducible verdict with reasons/sources) and names the alternative plus its selection condition: prefer this over get_forecast when no written narrative is needed. Explicit when and when-not.

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