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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely useful context beyond them: the connection requirement, the exact URL to resolve it, and the multi-account property-resolution behavior. It stops short of describing pagination or result shape, but for a read-only tool with annotations this is solid added value.

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 core purpose, then the prerequisite and edge-case behavior. No wasted phrasing; each sentence carries distinct information, though the connection instructions could be trimmed slightly.

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 read-only analytics tool with no output schema and full schema parameter coverage, the description covers the essential prerequisites and access nuances an agent needs. The device dimension is named and the connection dependency is handled, so nothing critical to correct invocation 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?

Schema coverage is 100%, so site, startDate, endDate, and searchType are already fully documented in the input schema. The description adds no syntax or format detail beyond the schema, so baseline 3 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 ('Get search traffic') and resource with the breakdown dimension (device type: desktop, mobile, tablet) made explicit. An agent can distinguish it from the many other get_gsc_* breakdowns because the dimension is named, though no sibling is called out by name.

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?

The description establishes a prerequisite (GSC must be connected) and how to fulfill it (direct user to rankparse.com/dashboard/integrations), which is real usage guidance. However, it gives no guidance on when to choose this device breakdown over the country/date-trend/page breakdown siblings, leaving that inference to the agent.

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