direct_report

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

With no annotations, the description carries the burden and does disclose a critical behavioral trait: the report may be generated asynchronously, with the tool polling and retrying for up to several minutes. It also flags that relative dates (e.g. 30daysAgo) are unsupported. It omits auth/permission requirements and error behavior.

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 purpose, then period semantics, then async behavior, in three dense sentences with little waste. The middle sentence is long, but every clause carries needed 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?

For a 7-parameter reporting tool with no output schema, it covers purpose, period formats, report types, and async latency well. Missing only auth/quota details and error/return expectations, which are minor given the schema documents all parameters.

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?

Schema coverage is 100% so baseline is 3, but the description adds real meaning: it explains the date_range-vs-date1/date2 choice, the LAST_30_DAYS default, and that relative date strings are rejected. This clarifies parameter interaction beyond the schema's per-field notes.

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 (a Direct spend/impressions/clicks report via Reports API v5) and explicitly distinguishes itself from the sibling direct_campaigns by noting it provides the real performance numbers that tool lacks. An agent can immediately tell what it returns.

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?

Names the sibling it complements (direct_campaigns) and clarifies it delivers effectiveness metrics by campaign/ad/group/search query, giving clear context for selection. It stops short of an explicit 'use this instead of X when Y' rule or stated prerequisites.

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