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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered. The description adds real behavioral context – the event taxonomy, per-event verdicts (or null), and the ordering/scope constraints – but doesn't discuss rate limits, output size, or pagination beyond the 31-day cap.

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 what/scope, then a tight event enumeration, then workflow, input contract, and disambiguation labels. Every sentence earns its place; nothing redundant.

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 complex multi-event timeline tool with a nested birth object and output schema, the description is complete: scope, event taxonomy, workflow position, disambiguation, input contract, and a docs link for the full contract.

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 100%, so every parameter is already documented with defaults, formats, and constraints. The description's INPUT CONTRACT restates defaults already in the schema (from_date defaults today, days 1-31 default 7, target_timezone defaults to birth tz) but adds no syntax or format detail beyond it.

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 (timeline of everything happening to a chart) with explicit scope (1-31 days, exact times), and enumerates the event types. Clearly distinguishes itself from siblings in the DO NOT CONFUSE WITH section.

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 an explicit workflow (BEFORE: get_natal_chart, AFTER: get_vedic_daily_factors) and names the two most confusable siblings (get_transits, get_dasha) with the reason each differs. This is the model for usage guidance.

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