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

Annotations already declare this a safe, idempotent, non-destructive read, so the safety profile is covered. The description adds genuinely useful context beyond that: the 10-credit Tier 1 cost and the fact that the caller must supply the eclipse track themselves. It does not address output form or the interaction between path and centerlinePoints, so it is moderate rather than rich.

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?

Two tight sentences followed by compact bracketed metadata; the core behavior is front-loaded and nothing is padded. The metadata block is dense but skimmable.

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 7-parameter nested tool with 29% schema coverage, the description is thin. An output schema exists so return values need not be explained, but key semantics — how `path` relates to `centerlinePoints`, what `options.theme`/`format` control, and the compact-mode fields/precision flags — are left undocumented.

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 29% across 7 parameters, so the description must carry more weight than it does. It gestures at `path` ('caller-supplied eclipse track') and `bandWidthDeg` ('band of given degree-width') but leaves `centerlinePoints`, `title`, `fields`, `precision`, and the whole `options` object unexplained.

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 gives a specific verb ('Renders') and resource ('centerline + shaded band' on an 'equirectangular world graticule'), making it clear this produces an eclipse-track map. It does not explicitly differentiate itself from siblings like astroway_render_star_map or astroway_geo_eclipse_analysis, but the eclipse-track framing is distinctive enough.

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 description gives no when-to-use guidance, no prerequisites, and no alternatives. The bracketed metadata only lists the required parameter, endpoint and cost, which is operational data rather than usage direction.

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