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

With no annotations provided, the description carries the full behavioral burden and does so well: it discloses provenance, distance, age, measured/predicted status, confidence, source divergence reporting, and that missing required evidence is named rather than silently estimated.

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 compact sentences with the primary action front-loaded. Each sentence earns its place: function, output guarantees, and missing-data handling. No filler.

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 description is strong for a no-annotation, no-output-schema tool: it explains what each returned value carries and how missing evidence is handled. It could be more complete by indicating the output shape or explicitly relating the tool to sibling scopes, but the core contract is sufficiently clear.

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 is 3; the description adds no parameter-specific meaning beyond the schema. It reinforces 'coordinate' and 'current', which aligns with lat/lng/time, but does not explain domain or time further.

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 uses a specific verb ('Return') and resource ('current physical-world evidence for a coordinate'), making the tool's core function clear. It does not explicitly distinguish itself from siblings such as check_operability or list_domains, so it misses the top score.

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 'current' and 'for a coordinate' language implies when the tool is relevant, but there is no explicit when-to-use guidance or contrast with alternatives. An agent must infer that this is the evidence-gathering tool among the siblings.

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