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

Annotations already declare non-read-only, non-idempotent, open-world; the description adds genuinely new behavior: PDF URLs expire after 24h via an auto-cleanup cron, branding overrides are applied when whitelabel is set, and the call is expensive (5,000 credits, ~50% of a free monthly budget) so user confirmation is required. Cost and output-lifetime disclosure is strong; the sentence explaining HTML mode is cut off mid-word.

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?

Dense, front-loaded and mostly waste-free: format and content come first, then branding, language and URL lifetime. It loses a point for a truncated trailing clause and for the language claim that conflicts with the schema, so not every sentence earns its place.

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 the description needn't describe return values, and the 24h URL note is a useful addition. But it is truncated, mismatches the language enum, and says nothing about failure/refund behavior for a 5,000-credit premium call, leaving an agent short of what it needs to invoke this confidently.

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 only 38%, so the description must compensate; it clarifies the format switch and whitelabel behavior but is silent on tone, length, enrich, fields and precision. Worse, it claims languages are 'uk (default) or en' while the schema enum lists 21 languages, which could steer an agent away from valid values. The nested `chart` object is richly self-documented in-schema, which partially offsets the gap.

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?

Opens with a specific verb+resource ('Render a Western tropical natal chart') and enumerates exactly what the artifact contains (Big Three, planets table with houses/retrograde, 12 cusps, major aspects). Western tropical vs. sidereal implicitly separates it from astroway_reports_vedic_kundli, but no sibling is named explicitly.

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?

Gives option-level guidance (PDF default, `?format=html` for live HTML, `whitelabel: true` for branding, language default) plus a premium-cost warning to confirm with the user first. However it never states when to choose this report over the many narrative siblings (astroway_reports_ai_natal_narrative, astroway_reports_generate), leaving the selection decision to inference.

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