space_calendar

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

With no annotations, the description carries the full burden and does well: it discloses the dual image+JSON return, that the tool does not query JPL itself and thus has data-accumulation semantics, that place is geocoded and rendered in local time, and it instructs the agent to surface image links verbatim and quote figure.notes without paraphrasing. It omits failure modes and any read-only/mutation framing.

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 one sentence, followed by a compact Args block that resolves each parameter in one line. The trailing presentation instructions (image links, figure.notes quoting) are brief and earn their place, though the bolded call-out about neo/fireball is slightly buried in the parameter list rather than surfaced up top.

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 six-parameter tool with no annotations and no output schema, this covers what an agent needs: what it returns, how categories behave, timezone/geocoding semantics, and output-handling rules. Minor gaps remain around error behavior when a place cannot be geocoded and around which location wins when both place and lat/lon are supplied.

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 must compensate, and it does: all six parameters are documented with meaning and defaults (year/month default to the observing location's current date, place defaults to Tokyo, lat/lon as numeric alternatives to place). Crucially, it enumerates the kinds values (user/launch/sky/neo/fireball/public/holiday/all), which the schema does not since there is no enum.

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 verb and resource: it returns a monthly calendar of space/astronomy events (launches, sky phenomena, public events, user events) as an image plus JSON. The category enumeration distinguishes its content from siblings like upcoming_launches or calendar_events, though it never explicitly says 'use this instead of X'.

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 mostly implied through the argument list; there is no explicit when/when-not guidance against siblings such as calendar_events or upcoming_launches. It does provide one genuinely useful usage caveat: neo and fireball categories only show previously accumulated data, so users must call neo_close_approach or fireball_reports first, and an empty month is not evidence of no events.

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