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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds useful operational transparency: deterministic 290+ checks, free/no auth, daily quota, and unsupported page types. No contradiction with annotations.

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?

The main action and return value are front-loaded in the first sentence, followed by concise constraints in the second. No filler or repeated schema information.

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 one parameter and no output schema, the description fully informs the agent what the tool returns and under what conditions it works. Minor omissions like exact error/rate-limit behavior keep it from a 5.

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?

The schema already covers the single URL parameter at 100%. The description adds meaningful constraints beyond the schema by specifying public URLs only, excluding localhost and login-gated pages, and implying an http(s) full URL format.

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?

Clearly identifies the action ('analyze a public web page') and the exact output: 0-100 quality score, letter grade, dimensions, and top issues. It does not explicitly compare itself to get_analysis or get_leaderboard, but its command semantics make it distinct enough.

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?

Gives strong contextual guidance: public pages only, no auth, free, and a 3-analysis daily limit. It also explicitly excludes localhost and login-protected pages. It does not name sibling tools as alternatives for retrieving prior results or leaderboards, so it stops short of a 5.

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