get_daylight

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

No annotations, so the description carries the burden. It discloses the shape of the return conceptually (categorical twilight states rather than a boolean) and explains why, which is genuinely useful, but it says nothing about whether times are returned as instants vs. local strings, what 'sun position' looks like numerically, or any rate/permission constraints. Read-only is inferable only from the 'get_' name.

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 sentences, front-loaded with the returned quantities, then a short design note that prevents a wrong expectation (boolean vs. four-state twilight). Nothing is padded.

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 no output schema and no annotations, the description does well to enumerate the returned quantities, but an agent still cannot predict the serialized form — time format of sunrise/sunset, units for sun position, or field names. For a 3-parameter lookup returning multiple values, that is a real gap.

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 33% — only 'at' is documented in the schema. The description adds only 'for a coordinate', which maps lat/lon to location but gives no sign convention, unit, or precision guidance, and never mentions the optional 'at' override or UTC/Earth-time handling.

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 concrete resource ('sun position, sunrise, sunset, and twilight state') with its required input ('for a coordinate'), which makes it unmistakable against siblings like get_weather and get_terrain. The clarifying note about how twilight is reported reinforces exactly what this tool returns.

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?

Usage is only implied: 'for a coordinate' and the twilight rationale hint at daylight/visibility decisions, but there is no explicit when-to-use, when-not-to-use, or named alternative (e.g., get_weather for cloud cover that would make twilight moot).

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