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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, and the description adds genuinely new operational context: the POST endpoint and a 50-credit Tier 3 cost. That billing disclosure is meaningful for an agent deciding whether to invoke. It stops short of describing response shape or any rate limits, but the annotation baseline is already covered.

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?

One tight explanatory sentence followed by compact structured metadata lines (group, endpoint, required, cost). Front-loaded and waste-free, though the bracketed metadata block is boilerplate rather than description.

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?

An output schema exists, so return values need not be explained, and cost/endpoint are covered. However, for a 7-parameter compute tool with low schema coverage, the undefined geometric parameters (azimuth, halfAngle, maxDistDeg) leave an agent unable to call it correctly without guessing.

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% (2 of 7 parameters documented). The description restates that latitude, longitude, and azimuth are required but never explains what azimuth means, nor what halfAngle or maxDistDeg control — leaving three numeric tuning parameters entirely opaque in both schema and prose. It compensates only marginally for the coverage 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?

States a specific verb (calculate) and resource (local space influence zone lines), plus scope (a chart relocated to a specific city, lines showing planet directions from that location). It is distinguishable from astroway_geo_local_space and astroway_geo_relocation, though it never names those siblings to sharpen the boundary.

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 phrase 'for a chart relocated to a specific city' implies the usage context, but there is no explicit when-to-use guidance, no when-not-to-use, and no reference to the nearby alternatives (astroway_geo_local_space, astroway_geo_relocation, astroway_geo_zenith). The agent must infer which geo tool fits.

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