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

With no annotations, the description carries the full burden, and it does add genuine value: size (~1,900 points), cadence (20-minute), span (~27 days), and the meaning of null entries. It omits failure behavior for an invalid puzzle_id and gives no access or rate-limit context.

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?

Three short sentences with no filler. It front-loads the return-value structure, which is the highest-value information given there is no output schema, though leading with the action rather than the payload would read slightly better.

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?

The return payload is well described despite having no output schema, which is the main completeness win. However, for a tool whose sole input is required and undocumented, and with no annotations, the definition leaves gaps around parameter sourcing and error behavior.

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 0% and the only parameter, puzzle_id, is never mentioned in the description. The agent is not told where a valid puzzle_id comes from (presumably planets_puzzles) or what form it takes, so the description only fills part of the gap for a one-parameter tool.

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 names a concrete resource (a single light curve) and its contents, so an agent can tell this apart from planets_puzzles (list) or planets_candidates quickly. It never states the verb explicitly ('retrieve the light curve for a puzzle_id'), but the combination of name and content description makes the operation unambiguous.

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 statement of when to call this versus siblings such as planets_puzzles or planets_candidates, and no note that a puzzle_id must first be obtained. The 'Large result' remark hints at caution but is not explicit guidance.

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