Get spend limits

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description contributes by naming the return contents (daily limit, dated windows, spent and remaining amounts), but adds nothing about auth requirements, caching, or rate limits. Note the description implies an implicit account context despite there being no account parameter.

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 front-loaded sentence with the resource stated first and the payload contents second. No filler, no repetition of the title.

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 output schema, the description carries the burden of describing returns and does so adequately by listing limits, dated windows, and spent/remaining amounts. The one gap is how 'the ad account' is determined given there is no account parameter, which an agent might need to know.

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 the baseline is 4. There are no arguments whose semantics need explaining, and the description correctly doesn't invent any. The only nuance - that the ad account is resolved from ambient/auth context - is left implicit.

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 ('Get') and resource ('the ad account's daily spend limit and dated spend-limit windows') and enumerates the returned fields (amounts spent and remaining). This clearly separates it from generic siblings like get_ad_account or account_summary, though it doesn't explicitly name 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 subject matter - an agent should call this when it needs spend limits - but there is no explicit when-to-use, when-not-to-use, or alternative routing. Given the tool is a narrow 0-param read, this is acceptable but not instructive.

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