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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely non-obvious behavior: the call refreshes the ChatGPT card, and it imposes framing rules ('always say you have X credits', never imply a USD wallet), which is real context beyond the structured fields.

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 short sentences with no padding, and the terminology constraint (credits vs. bank balance) is front-loaded. The mix of definition, trigger, and phrasing rules is slightly scattered but each sentence carries intent.

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?

An output schema exists and annotations cover the safety profile, so the description need not explain return values. It covers the one genuinely confusing point (credits are not USD) and the refresh trigger, leaving only the implicit statement of purpose as a gap.

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?

Zero parameters, so the baseline is 4. Nothing in the description conflicts with the empty schema and no parameter meaning is needed or missing.

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 title 'Credit balance' plus 'credits are in-app points for renting numbers' defines the resource and terminology, but the description never states the actual operation — that it retrieves/reports the current credit balance. 'Linked wallet' is ambiguous as an opener and an agent must infer the verb from the name. It is distinguishable from ucode_agent_wallet only by implication.

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 one concrete trigger ('After the user adds credits on the dashboard, call this so the ChatGPT card refreshes'), which is useful, but it never says when NOT to use it or names alternatives such as ucode_agent_wallet, ucode_render_credits, or ucode_credit_gift_breakdown, which are the closest siblings. Usage is implied rather than fully routed.

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