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

Annotations declare readOnlyHint=true, and the description is consistent with a pure metadata-read tool. It adds genuinely useful behavioral context beyond annotations: the mandatory prerequisite ordering, and the fact that the accounts response already contains available_actions so a separate call is only for standalone use. It does not discuss response size, caching, or what happens if actions_details is skipped.

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?

Numbered steps with the mandatory path first and optional branches clearly marked make it easy to scan and act on. Slightly verbose with placeholder 'xxxxxx' values and a repeated explanation of available_actions, but nearly every sentence carries operational value.

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?

This is a multi-mode router tool with five parameters and an output schema, so the description must supply the mode-selection logic; it does so completely for four of the five parameters and both required and optional flows. The unaddressed platform parameter is the one real gap, and return-value documentation is rightly omitted because an output schema exists.

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 0%, so the description carries the full burden and largely succeeds: it explains request enum values, defines actions as IDs drawn from available_actions (the example array shape is shown), and pairs brand_id with workspace_id for the brands mode. The 'platform' parameter is never mentioned anywhere, leaving one of five parameters opaque.

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 states precisely what the tool is for: a planning/lookup helper for GSC queries, and enumerates the four request modes with what each returns (accounts gives workspace_id, brand_id, site_url, available_actions; actions_details gives request body, identifiers, fields). It implies the boundary with query_data/execute_action via the 'REQUIRED before querying' sequencing, but never names a sibling outright, keeping it 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?

Explicit ordered workflow: Step 1 accounts, Step 2 actions_details marked REQUIRED before querying, plus two clearly labelled optional calls and the condition for each (brands requires brand_id + workspace_id). It also tells the agent that available_actions is redundant with the accounts response, preventing a wasted call.

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