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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely non-obvious context: that the Chrome extension is what actually executes indexing clicks, which changes how an agent should interpret a completed or failed request_indexing call. It says nothing about auth requirements or whether quota counts are cached/stale.

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?

One dense sentence covering the key returned fields, with the most decision-relevant facts (plan, budget, extension online) listed first. It is slightly elliptical — a fragment rather than a sentence with a verb — but no clause is padding.

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 appropriately enumerates the returned data points, including the Google quota comparison an agent needs for planning. The main gap is the absence of any guidance on when to call it relative to other tools.

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% and the single optional 'tz' parameter is fully documented in the schema. The description never mentions time-zone handling, so it adds nothing over the schema here; 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?

The description enumerates the specific resources the tool reports on: plan, key permissions and hourly budget, Chrome extension online state, and today's per-site request counts vs Google's daily quota. That is concrete and clearly distinct from action-oriented siblings like request_indexing or cancel_indexing_request. It omits an explicit verb ('returns'/'reports'), but the scope is unmistakable.

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?

There is no stated when-to-use or when-not-to-use guidance, and no sibling is named. The clause about the extension performing 'every Request indexing click' hints that this tool explains why request_indexing may fail, but the agent must infer that routing itself.

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