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

Annotations already declare readOnly, idempotent, non-destructive and open-world. The description adds meaningful behavior beyond that: it only reads public assets, never logs in, submits forms or probes private routes, which tells the agent the scan is safe but limited in coverage. It omits rate limits, runtime expectations and what happens on sites that are not AI-built.

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?

Two sentences, both front-loaded with the most decision-relevant information: what is scanned and reported, then the passive-safety constraint. There is no filler or repetition of the title.

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 compensates by enumerating the report categories an agent should expect. Combined with the stated passive scope, an agent can decide and call confidently; only operational details such as timing or failure modes are absent.

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 each parameter carries its own description, so the schema does the heavy lifting. The description adds only indirect meaning: the mention of 'AI model calls made from the browser' hints at what sends_user_data_to_ai feeds into, but the url and language parameters get no elaboration.

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 opens with a concrete verb-plus-resource ("Reads the public pages and public JavaScript of a web app") and then enumerates the exact findings it reports, so an agent knows precisely what this produces. The parenthetical list of build platforms (Lovable, Bolt, v0, Replit) further pins the target compared with the email-security and Shopify siblings.

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 clear applicability context (apps typically built with AI tools) and a scope boundary via the passive-check statement. It never names the sibling tools or states when to route elsewhere, so there is no explicit exclusion or alternative guidance.

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