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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the bar is lower, yet the description still adds substantial behavioral context: browser-like rendering of the site, ~1 minute runtime, explicit failure mode (site down or blocking bots yields no score), a daily per-person and per-site rate limit, and the shape of the result. This is exactly the context an agent needs to set expectations and handle failures.

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?

Front-loaded with what it does and returns, then layered with triggers, coverage areas, latency, safety, failure behavior, and limits, all in short sentences. Slightly padded by two overlapping trigger sentences and a read-only restatement that annotations largely cover, but nothing is genuinely wasteful.

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 carries the return-value burden and does so: score out of 100, up to three prioritized problems each with a rationale, plus the no-score failure case. Combined with runtime, scope, and rate limits, an agent can invoke and interpret this tool without guessing.

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% and the single url parameter is already documented with examples and length bounds. The description adds no format or normalization guidance 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 and resource ('Checks a public small-business website') and immediately scopes it with the return value (score out of 100, top three problems) and the six areas examined. An agent knows exactly what this tool produces. It does not, however, name or contrast with its sibling explain_area, which is the one differentiation an agent would benefit from.

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 concrete trigger conditions, including paraphrased user utterances ('whether their website is any good', 'why isn't my site bringing in customers?', 'audit a website'), which is unusually strong routing guidance. It stops short of stating when NOT to use it or pointing to explain_area as the alternative for understanding the six areas.

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