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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds essentially nothing beyond that: it does not say whether one or many calculators are returned, what happens when query is omitted, or how the discovered calculator feeds later calls. With an output schema present, return-shape detail is not required, but invocation behavior still is.

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?

A single front-loaded sentence with no filler or redundancy. The terseness, however, means content is missing rather than that the sentence is efficiently packed.

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 discovery tool that gates a whole calculation workflow, the definition is too thin: the sole parameter is undocumented and there is no link to run_calculation or prepare_calculation. Relying on the output schema to explain results is reasonable, but everything about how to call and when to call it is absent.

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?

Only one parameter exists (query, optional) and schema description coverage is 0%, so the description carries the burden of explaining it. It does not — the single sentence never mentions the query argument, its expected format, or what an empty query yields. The low parameter count keeps this from being worse than a mid score.

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 supplies a concrete verb and resource ("Finds ... calculator") and scopes it to "a UK building task", so the broad intent as a discovery/lookup tool is legible. However, "narrowest deterministic" is never defined, and it does not distinguish this from siblings like prepare_calculation, run_calculation, or compare_calculations, leaving the agent unsure how this differs from the actual calculation tools.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The agent is not told that this should be called before run_calculation or prepare_calculation, nor what to do with the result once found, so the routing decision is left entirely to inference.

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