iss_now

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

With no annotations, the description must carry the behavioral burden; it does signal a side-effect-free read by saying it "returns" the position and "generates" a URL. However, it says nothing about data freshness/update cadence, units or coordinate format, or the response shape, which matter for a 'current position' tool.

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?

One compact sentence covering purpose and output, followed by a short example-query line. Both earn their place, though the example line is somewhat redundant with the first 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?

No output schema exists, so the description does well to mention both deliverables (position and map URL). For a zero-param read tool this is nearly sufficient; only freshness and return-format details are missing.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The empty schema matches the description's implication that the call needs no arguments.

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?

States a specific verb and resource ("returns the current position of the ISS") plus a secondary output (a Google Maps URL), so the agent knows exactly what it gets. It does not differentiate from close siblings such as tiangong_now (same function for another station) or sat_tle/sat_ground_track, leaving that inference to the caller.

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?

The sample utterances ("Where is the ISS now?", "current position of the International Space Station") give concrete trigger conditions for when to invoke this tool. No explicit when-not or alternative-tool routing is provided, so it stops just short of full guidance.

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