Views, uniques and clicks

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

Beyond the readOnlyHint/destructiveHint=false annotations, the description discloses that results are served from rollups and are therefore constant-size regardless of traffic, and that the call requires the analytics.read grant. It also warns that all-zero results usually indicate a tracking failure. This is meaningful operational context.

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 purpose before the return shape, then the rollup behavior, then the escalation rule and grant requirement. Every sentence adds information an agent can act on; there is no filler.

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 usefully sketches the return shape (totals, daily series, top posts) and names the required grant, so an agent can call it confidently. It stops short of describing key names or whether the series can be sparse, but nothing essential 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 description coverage is 100%, so all four parameters (projectId, from, to, topPosts) already carry their own descriptions, defaults, and bounds. The description's phrase 'over a date range' adds no format or boundary detail beyond the schema, so the baseline of 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+resource ('What readers did with a project's posts') and enumerates the shape of the answer: totals, a daily series, and best-read posts. It implies project-level scope, which separates it from the per-post sibling get_post_analytics, but it never names that sibling, so the differentiation is inferred rather than stated.

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?

It provides a concrete when-to-escalate rule: if everything is zero, call check_integration, with the reasoning that it is usually a tracking problem. That is real routing guidance, but it gives no guidance on when to prefer this aggregate view over the sibling get_post_analytics for a single post.

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