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

Annotations already establish read-only/idempotent/non-destructive, yet the description adds real behavioral content: it explicitly says it does not reserve or consume quota, and prescribes the unlimited-plan edge case (report unlimited, suppress limitUnits/availableUnits, keep deviceLimit and executionSlots limited). That is behavior beyond what the annotations convey.

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 sentences, front-loaded with the usage trigger, then the safety note, then the edge case. Every sentence carries distinct information with no padding.

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?

There is no output schema, so the description must carry return-value semantics — and it does, naming the relevant response fields and the unlimited-plan interpretation rule. Combined with annotations covering the safety profile, nothing needed to call or interpret this tool is missing.

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 nothing for the description to disambiguate; baseline 4 applies. The field names it references (limitUnits, availableUnits, unlimitedExecutions) belong to the response, not the input schema.

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 — reads how much managed execution allowance is reserved, consumed, or available for the authenticated tenant. No sibling tool touches quota/allowance, so the resource is unambiguous and an agent can route to it without opening the schema.

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?

Opens with an explicit trigger: 'Use this when the user asks how much managed execution allowance is reserved, consumed or still available.' It also gives the conditional branch for the unlimitedExecutions case, so the agent knows both when to call it and how to interpret the answer.

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