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

No annotations are supplied, so the description carries the full load. The examples communicate valuable behavioral context: the tool accepts free-form natural language and symbolic expressions alike, is a pure computation with no side effects, and handles time-zone-aware requests. It never states the return format, whether results are deterministic, or how unparseable queries are reported.

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 sentence, front-loaded with 'Calculator:', then dense parallel example groups where every example demonstrates a distinct capability. No filler, no repetition — each clause earns its place.

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 one-parameter, annotation-free, output-schema-free tool, the input domain is covered thoroughly. The only real gap is that return values are not described at all — acceptable for an obvious numeric/text result, but a sentence on output form would close the loop.

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 single parameter 'q' has no schema description at all (0% coverage), so the description must compensate, and it does: the example strings show precisely what belongs in 'q' across all supported capabilities. It adds meaning well beyond the bare string type, though it does not define grammar rules or quoting requirements.

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 the tool as a calculator and then enumerates its concrete domains: math expressions, percentages, unit conversion, time zones, and date arithmetic. That scope is specific enough to separate it from every sibling (messaging, notes, agents), though it uses example lists rather than a single declarative verb+resource sentence.

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?

Usage is implied only by the example categories: an agent can infer 'use this for arithmetic, conversions, and date math.' There is no explicit when-to-use framing, no statement of what the tool should NOT be used for, and no alternatives mentioned among siblings.

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