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

No annotations are supplied, so the description carries the full disclosure burden and mostly does not meet it. It says nothing about how the three datasets are merged in the response, what happens if one source is unavailable, whether lat/lon and port are mutually exclusive selectors, or any defaults or limits.

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 short sentences, front-loaded with the capability and followed by the routing rationale. Nothing is padded, though the second sentence is a soft sales claim rather than additional specification.

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 five-parameter aggregation tool with zero required parameters, no annotations and no output schema, the description covers the what but not the how. The unresolved question of when to use lat/lon versus port, and how partial results are returned, leaves real gaps an agent must guess at.

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 100%, so the baseline applies: lat, lon, days, port and include are already documented in the schema. The description adds no meaning beyond it and notably does not clarify the important lat/lon versus port selection semantics, which the schema also leaves implicit.

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 specific verb and a concrete union of resources (weather, marine, astronomy) in a single call, which distinguishes it from the single-domain siblings get_weather, get_marine and get_astronomy. It stops short of naming those siblings by tool name, but the intent is 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?

It explicitly positions itself against the alternative path ('more efficient than calling each separately'), giving the agent a clear selection rule. It omits the reciprocal case, e.g. that if you only need one data type, a dedicated sibling call is cheaper.

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