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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds real value beyond them by naming the returned limit fields and explaining the 'limited' flag's semantics ('limited is false when there are none') — response-shape information that matters because no output schema exists. It stops short of describing rate limits or auth requirements.

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 sentence with the core resource front-loaded, followed by the returned fields and one clarifying edge case. No filler, no repetition of the title, and every clause carries information.

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?

With no input parameters and no output schema, the description correctly carries the return-value burden by naming the limit fields and the 'limited' flag semantics; safety is covered by annotations. It still leaves other response fields (e.g. how spend is reported) unspecified, but for a simple zero-arg read this is close to complete.

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, which sets the baseline at 4. The description correctly uses its space to describe outputs instead of inventing parameter behavior, so there is no gap to compensate for.

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 names a specific resource (spending limits the account owner set on you) and states exactly what is returned (spend_limit, daily_spend_limit, max_task_value plus spent amounts). It is clearly distinct from siblings like get_balance or get_me, though it does not explicitly contrast itself with them. A specific verb is only implied by the plural-noun framing, keeping it just short of a 5.

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?

Nothing states when to call this versus get_balance, get_me, or get_readiness, nor any precondition such as needing an owner relationship. Usage is only inferable from the resource name. For a zero-argument read tool, one clause about when it matters would have been cheap to include.

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