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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds useful substance by listing exactly which fields are returned (URL, category, style, stack, palette, fonts, sections, screenshot link). It stays silent on result ordering, pagination beyond the limit cap, and the combining logic of multiple filters.

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, zero padding. The purpose is front-loaded and the second sentence is a compact, high-value enumeration of the response shape rather than restating the name.

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 eight optional parameters and no output schema, the description carries the right load by describing both the filter surface and the return fields. Gaps remain on how multiple filters compose and what happens when the query matches nothing, but an agent has enough to call it correctly.

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 88%, so the schema already documents nearly every parameter, which sets the baseline at 3. The description does contribute beyond schema by glossing the semantics of `section` ("sites with a captured pricing page") and `query` ("product name or industry") and by implying filters are AND-combined with "and/or"; `limit` receives no mention anywhere.

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 ("Find real SaaS marketing websites") plus its intended use as design references, and enumerates the returned fields so the agent knows exactly what it gets back. It does not explicitly name its siblings (get_site for a single site, list_filters for facet values), so the differentiation is implied by the plural search framing 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?

Gives clear context for when the tool applies (browsing sites as design references, with an explicit list of admissible filter facets) and even points to list_filters for the category vocabulary. It stops short of saying when to prefer get_site or list_site_links instead, so there are no explicit exclusions.

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