Get SendKuy account

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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds value beyond that with a real behavioral caveat: plan, credits, and usage are null for staff keys, which prevents an agent from misreading nulls as an error. No mention of rate-limit behavior on the call itself, keeping it below a 5.

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?

Front-loaded with the resource and its return contents, then the usage cue, then the caveat — a sensible order with no filler. The second mention of 'plan, credits and usage' mildly restates the opening enumeration, costing a little tightness.

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-param read tool with annotations and an output schema, everything an agent needs to decide and invoke is present: what it returns, when to call it, and how to interpret nulls. No gaps remain.

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 and schema coverage is 100%, so there is nothing for the description to compensate for. Baseline for a no-param tool applies.

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?

States a specific verb and resource ('Read the SendKuy account behind this API key') and then enumerates exactly what is returned: plan, per-channel credits, period usage, rate limit, and key scopes. This is clearly distinguishable from the message/campaign siblings, which all act on messages rather than account state.

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?

'Check credits before a large send' gives an explicit trigger condition tied to a concrete sibling action (batch/send), which is real guidance rather than an implied use. It stops short of naming the sibling tools or stating exclusions, so it falls just under the top mark.

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