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

Annotations already establish readOnly=true, destructive=false and closed-world, so the safety profile is covered. The description adds genuinely new behavioral detail the annotations cannot carry: the return contains two lines, the site token is already embedded in data-site, and data should appear in the dashboard Website tab within a minute of the first visit — a verification loop an agent would otherwise lack.

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 compact blocks: purpose, handling instruction, verification step. Purpose is front-loaded and each sentence carries an action an agent needs. The lack of sentence-terminating punctuation on a multi-clause first sentence makes it slightly dense, but 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 must characterize the return value and does so well (the script tag, both lines, embedded token). For a one-parameter read tool with full annotation coverage this is nearly sufficient; the only remaining gap is the absence of any alternative-tool routing or handling of a product without a website.

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?

There is a single parameter with 100% schema description coverage ('The product key (see list_products)'), so the schema does the documentation work. The description adds only indirect meaning via 'a product's own website' and does not explain what happens if the product has no site configured; 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 names the concrete artifact ('the exact <script> tag that installs krawlup first-party analytics') and what it measures (visitors, sessions, pages, referrers, countries, conversion goals), so an agent knows precisely what it gets back. It falls short of 5 because it never distinguishes itself from the sibling get_analytics_token, which an agent could reasonably confuse with it.

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 gives a clear context of use — installing analytics on a product's own website — and procedural directives about inserting both lines and never asking the founder to paste the token. It never states when NOT to use it or points to the alternative (get_analytics_token) for a raw token need, so routing between siblings is left to inference.

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