coverage

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

With no annotations, the description carries the full behavioral disclosure burden. It reveals that the tool accepts three ref formats and ties the coverage window to query refusal, which is useful context. However, it does not describe what the tool returns, whether it is read-only, or what happens on invalid references, leaving meaningful gaps.

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 description is compact and each sentence contributes: the core concept, accepted input forms, and a usage directive. The first sentence is slightly cryptic, but the overall structure is efficient and free of 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?

For a single-parameter tool, the description covers the accepted ref formats and the key use case of checking coverage before promising a range. An output schema is present, so the lack of return-value details in the description is acceptable, though a short example would make it even more complete.

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 input schema only provides the parameter name 'ref' with no description, so the description adds essential meaning by specifying that ref can be a table.column, entity.attribute, or definition name. This is strong value beyond the sparse schema, though it stops short of giving concrete examples or formatting rules.

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 defines coverage as 'the seasons a thing can answer for' and lists accepted reference forms, which conveys that the tool returns or checks time coverage. However, it never uses an explicit verb like 'returns' or 'checks,' and the metaphorical 'seasons' language is vaguer than needed to distinguish the tool's exact function clearly.

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 description gives concrete usage guidance: 'check here before promising a range' and explains that queries are refused when they fall outside the coverage window. It clearly communicates when the tool should be called, even though it does not explicitly name alternative tools for other scenarios.

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