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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's added value is in disclosure of content: verified country lines, free online options that work anywhere, and US/UK debt-advice services. It also flags that verification is manual and coverage may be partial ('where verified'). It stops short of saying what happens with an unrecognised country code, which is the remaining gap.

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?

Three sentences, each doing distinct work: provenance, when to use, what comes back. The trigger conditions are front-loaded and no sentence is redundant or restates the title.

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?

With no output schema, the description carries the burden of describing returns, and it does so reasonably well (lines, online options, debt advice). Minor gaps remain around behaviour for unknown or unsupported countries and whether results can be empty, but the definition is sufficient to invoke correctly.

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% and the single country parameter is fully documented in the schema, so the baseline is 3. The description adds meaning by explaining that non-country-specific online options are returned regardless, which tells the agent that omitting the parameter still yields useful results — a behavioral fact the schema does not convey.

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 resource (free, confidential gambling helplines and crisis lines) and a specific scope (per-country, hand-verified), which is immediately distinguishable from siblings like block_gambling or gambling_self_check that operate on the user's own gambling. An agent can tell what this returns without opening the schema.

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?

It gives concrete triggering conditions: someone wants to talk to a person, is struggling after losses, or seems in distress. That maps a real conversational situation to this tool rather than to the self-check or blocking siblings, so selection is unambiguous.

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