cycles_check_balance

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

With no annotations, the description carries full burden. It discloses the output and required filters, but does not explicitly state that the tool is read-only or describe pagination behavior (cursor, limit) or authorization needs.

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 concise sentences, no fluff. First sentence states purpose and return, second gives requirement, third provides critical warning. Well-structured and efficient.

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 tool with 9 parameters, no output schema, and no annotations, the description covers the core function and warns about balance changes, but lacks detail on pagination (cursor, limit) and the includeChildren parameter. Output fields are listed but return structure is not fully described.

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 description coverage is 0%, so description must compensate. It lists filter types and notes one is required, but does not explain individual parameters like limit, cursor, or includeChildren. Many parameters remain undocumented.

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 clearly states the tool checks a budget balance for a scope and lists the returned amounts (remaining, reserved, spent, allocated, debt). It distinguishes from sibling tools like cycles_reserve by emphasizing it is a read-only check.

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 specifies that at least one subject filter is required, and warns not to use as a substitute for cycles_reserve due to balance changes. This provides good context for when and when not to use, though explicit alternatives are not listed.

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