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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful operational context the annotations lack — the endpoint (POST /v1/algol-minimum) and the cost (10 credits, Tier 1) — but says nothing about the response or any computation caveats.

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?

The core sentence is front-loaded and free of padding, and the bracketed metadata block (group, endpoint, required params, cost) is compact and scannable. Slightly over-formatted for the amount of substantive content, but nothing is wasted.

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 the endpoint/cost block is a plus. Still missing are sibling disambiguation against algol_minimum_nearest and any explanation of the longitude parameter, both of which an agent needs to call this correctly.

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 40%: startDate and endDate carry no descriptions beyond a date regex, and the longitude parameter is completely undocumented in both schema and description — its role in an Algol-minimum calculation is unexplained. The description only restates that startDate and endDate are required and adds no format or semantic detail, so it fails to compensate 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?

The description gives a specific verb and resource — finding the nearest minimum-brightness moment of Algol within a date range — and even identifies the star (Beta Persei, an eclipsing variable). However, it does not differentiate itself from the close sibling astroway_calendar_algol_minimum_nearest, which an agent could easily confuse with this tool given the near-identical name.

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?

No when-to-use, when-not-to-use, or prerequisite guidance is provided. The obvious alternative, astroway_calendar_algol_minimum_nearest, is never mentioned, leaving the agent to guess which of the two Algol tools matches its intent.

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