check_balance

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe read-only nature is known. The description adds context about returning balance/remaining allowance, but does not disclose specifics like response format or whether the provider parameter is a name or ID. With annotations covering safety, this description provides minimal additional behavioral context beyond the purpose, warranting a mid-range score.

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 description is a single concise sentence that is front-loaded with the action and resource. It contains no redundant words or filler, every word contributes meaning, and it is appropriately sized for the tool's simplicity.

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?

The tool is simple with one parameter, an output schema exists, and annotations indicate read-only behavior. The description clearly states the core purpose and scope. While it lacks usage guidelines and parameter details, these are partially covered by the presence of sibling tools and the output schema. Overall, the description is sufficiently complete for a basic balance-check tool, though not exhaustive.

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 schema has one required parameter 'provider' with no description, and schema coverage is 0%. The description says 'for a provider', which clarifies that the parameter identifies the provider, but it does not define what values are acceptable, whether it is an ID or name, or how it relates to business logic. This is insufficient compensation for the zero coverage, leaving the agent unsure about parameter semantics.

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 uses a specific verb ('Check') and clearly identifies the resource ('account balance / remaining traffic allowance') and scope ('for a provider'). It distinguishes itself from siblings like 'get_usage' by focusing on balance/allowance rather than usage. The phrasing is unambiguous and directly states the tool's function.

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?

The description does not provide any guidance on when to use this tool versus alternatives. There is no mention of related tools such as 'get_usage' or 'list_providers', nor any exclusions or prerequisites. The usage context is only implied by the tool's purpose, leaving the agent without explicit decision support.

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