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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds one genuine behavioral trait beyond annotations: the data is cached, so results may be stale or absent. It stops short of saying what happens on a cache miss (error vs. empty).

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?

A single front-loaded sentence with no filler; the key qualifier ('Cached') leads. The parenthetical about the on-page grader is mildly redundant but still informative about provenance.

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 'content-grade summary' remains vague about what fields or score shape come back. Combined with no cache-miss behavior, it is adequate but not complete enough for a tool whose result structure is entirely undocumented.

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% with both parameters documented ('Exact URL to look up', 'UUID of the site'), so the schema does the heavy lifting. The description's phrase 'for a URL on a site' merely restates the same two inputs without adding format, matching, or normalization guidance.

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 a specific resource (a content-grade summary) and its scope (a URL on a given site), plus the origin ('from the on-page grader'). An agent can tell it returns a grading result rather than raw content or audit issues. It does not explicitly contrast with siblings like get_site_audit or get_cwv, so it stops short of a 5.

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?

'Cached' weakly implies this reads a previously computed grade rather than triggering a new one, which is useful context. However, there is no explicit when-to-use, no prerequisites (must a scan have run first?), and no named alternative such as start_scan or get_site_audit.

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