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

Annotations already declare read-only, open-world, non-idempotent, non-destructive. The description adds real value beyond that: it discloses a network fetch of a live page, the nature of the output (severity per entity, entity counts, a score), and that microdata/RDFa are counted but not validated. Missing only failure modes (unreachable page, no JSON-LD present).

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, front-loaded with the core action and followed by the secondary output. The 'without validating them' qualifier earns its place by preventing a misuse.

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?

A single-parameter tool with an output schema, where the description covers action, scope, and exclusion clearly. It is only marginally short of complete for omitting what happens when the page is unreachable or contains no JSON-LD.

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 0% and the single 'url' parameter has no schema description, so the description must compensate. 'Fetch a page' implies url is the page to fetch and validate, which is the minimum needed, but it adds no format, scheme, or reachability constraints.

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 chain (fetch, validate, report) and resource (JSON-LD entities against schema.org types) with the exact output shape (per-entity findings with severity, counts, score). No sibling tool does this, and the description makes that scope unmistakable.

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?

The scope boundary is stated clearly ('also reports how many microdata and RDFa annotations are present, without validating them'), which tells an agent what this tool will NOT check. But there is no explicit when-to-use guidance, no prerequisites, and no named alternative among siblings.

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