tonight_highlights

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

Annotations cover readOnlyHint and openWorldHint, so the safety profile is already handled. The description adds real behavioral context beyond that: results carry tonight's imaging windows with moon illumination and distance, moon_dist_min accepts the API's avoidance presets, and raw=True returns the untrimmed payload. It does not mention rate limits, pagination, or failure modes, but the added return-shape detail is substantial.

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?

Purpose is front-loaded in the first sentence and the remaining lines are compact, field-by-field note fragments with no filler. The telegraphic style is efficient, though the parameter notes are not visually separated from the summary sentence.

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 9-parameter, output-schema-less tool, the description covers what the results contain and how the filtering knobs behave, which is most of what is needed. It omits how date/timezone interact with 'the given night' and what happens when lat/lon are omitted, so an agent must guess at the location/time 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 description coverage is 0%, so the description carries the full burden, and it delivers meaningful semantics for 5 of 9 parameters: types format and example values, min_alt units, min_alt_minutes' relationship to min_alt, moon_dist_min's preset strings, and raw's effect. It leaves lat, lon, date, and timezone unexplained, which is a real gap for a location- and time-sensitive tool, but the covered half is documented well beyond the schema titles.

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 opening sentence states a specific resource and scope: Telescopius' curated popular targets that are well placed on a given night. That is more precise than a tautology and conveys 'curated list, not arbitrary search'. However, it never distinguishes itself from plausible siblings like search_targets or event_highlights, so an agent cannot tell from the text alone which of the two 'highlights/search' tools fits a given request.

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?

There is no explicit when-to-use or when-not-to-use guidance and no alternative tool is named, despite 11 siblings including search_targets and event_highlights. The scoping filters described (altitude, moon separation) imply a 'tonight's recommended targets' use case, but usage is left entirely to inference.

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