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

Annotations already declare readOnlyHint and openWorldHint, yet the description still adds real context: ~1 s latency, the full return field list, null behavior for page_timing_ms, and what does and does not count as a failed check. Auth, rate limits, and error behavior are not covered, so not a 5.

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 purpose and speed, then return fields, then the sibling exclusion. The long enumeration of page_timing_ms subfields is the only slightly padded section, but each line still carries 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?

Even though an output schema exists, the description supplies the semantics an agent needs (checks_failed meaning, positive flags excluded, timing null case, latency expectation). Little is missing for correct invocation; only auth/error handling is absent.

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%, so the description must carry the burden; it explains that workspace is a client slug and is optional when only one workspace exists. 'url' is left implicit, but its meaning is self-evident from the audit context.

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 ('Schneller Live-On-Page-Audit ~1 s') plus the exact signals it returns (Title, Meta, H1, Word Count, OnPage-Score, Issues). It clearly distinguishes itself from dfs_lighthouse_live and dfs_onpage_crawl by speed and scope.

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?

'Erste Wahl für schnelle Seiten-Checks' states when to pick it, and 'Keine Core Web Vitals und kein Performance-Score — dafür dfs_lighthouse_live' names the sibling to use instead with the condition that selects it. The workspace note clarifies the optional parameter's situation.

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