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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the dataset is restricted to currently active, official coupons and includes their descriptions and applicability, which tells the agent what will and will not come back.

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 tightly written sentence with the resource and its scope qualifiers front-loaded. No filler, no restatement of the title, nothing that could be cut without losing meaning.

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 zero-parameter read-only tool with full annotation coverage and an output schema, the description carries enough: what it returns, and that results are limited to active official coupons. The only gap is the missing routing hint toward validate_coupon, which keeps it short of a 5.

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?

There are zero parameters, so there is nothing for the description to disambiguate and the 4 baseline applies. The description correctly avoids inventing filter parameters that the empty schema does not support.

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 a specific verb ('Retrieves') and resource ('currently active official ConnectMeGuru promotional coupon codes'), and the scope qualifiers make it clearly a listing operation rather than a single-item lookup. It does not explicitly distinguish itself from the sibling validate_coupon, so an agent has to infer the split between listing active coupons and validating a specific one.

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 only implied by the 'currently active' scope — the description never states when to call this instead of validate_coupon, nor any prerequisite or exclusion. An agent can reasonably infer 'browse available coupons' vs 'check one coupon', but the routing is left to inference rather than stated.

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