Credit balance

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

readOnlyHint=true already covers the safety profile, so the bar is lowered. The description usefully discloses what the call returns (balance, per-connection spending limits, recent movements), which matters because there is no output schema, but it says nothing about freshness, window size for 'recent', or result format.

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 compact phrase-fragment that front-loads the primary resource (credit balance) before the secondary details. Nothing is padded, though it is a fragment rather than a complete sentence.

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 no output schema, the description covers the key question of what data comes back. Only the shape and time window of the returned figures are left unstated, which is a minor 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?

The tool takes zero parameters, so there is no parameter semantics to document; the baseline of 4 applies. The schema is empty and fully consistent with the parameterless description.

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?

Names the specific resource being retrieved (credit balance) and enumerates the scope: spending limits for this connection plus recent credit movements. An agent can distinguish it from list_credit_packs or quote_generation, though it never explicitly contrasts itself with those siblings.

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 implied by the enumerated contents — an agent knows to call this to inspect credits or spending limits — but there is no explicit when-to-use statement, no prerequisites, and no guidance on how it relates to alternatives such as list_credit_packs.

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