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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it names the return artifact (match percentage plus summary text), discloses that richer advice is gated behind paid plans, and states a cost of 1 credit — a real constraint an agent would otherwise not know.

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 substance is compact, but the opening redundantly restates the tool name twice ('Love Calculator: Love Calculator calculates...') before getting to the point. The remaining sentences each carry information (output, tier gating, credit cost), so the waste is limited to the lead-in.

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 simple two-parameter, read-only novelty tool with an output schema already present, the description covers inputs, output shape, cost, and tier differences — essentially everything needed to call it correctly. Only selection guidance relative to other entertainment tools is 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?

Schema coverage is 100% with two clearly documented string parameters, so the schema carries the parameter burden. The description only adds that arbitrary names (as opposed to registered users) are acceptable, which is a marginal clarification beyond the schema; the baseline of 3 applies.

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: calculates romantic compatibility between two names, returning a match percentage and summary text. The operation is unmistakable and no sibling tool competes for this niche, though the description does not explicitly distinguish itself from adjacent novelty tools such as Horoscope or FortuneTeller.

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 guidance on when to use this tool versus alternatives, and no exclusions or prerequisites are stated. The only contextual detail is the paid-tier note, which is about output depth rather than when to select the tool.

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