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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the bar is lower. The description still adds real value: 'No provider requests' clarifies this reads saved/cached data rather than hitting providers, and 'unknown measurements are null' discloses the missing-data behavior.

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?

Only two sentences, but they are overloaded with cryptic phrases like 'named legacy literal table rates' and 'hash-verified escaped-underscore audit', and the clause 'The legacy table gap is not demonstrated structural loss' is a disclaimer that does not clearly earn its place in a front-loaded definition.

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?

It gestures at what is returned (measurements, source dates, audit, limitations, disclosed buyer links) and there is no output schema to lean on, so some coverage is needed. But the obscurity of the legacy-table and audit references leaves the agent unsure what the tool actually produces or when it is the right choice.

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?

The tool takes zero parameters, so the schema has no parameter semantics to convey and the baseline is 4. There is nothing the description could add about inputs.

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 verb 'Read saved ... extraction measurements' and the resources (Firecrawl, Jina Reader, DIY RAG) give a workable sense of the tool, and it is nominally distinct from siblings like compare_proxy_providers and compare_scraping_apis. However, the purpose is buried under dense jargon ('named legacy literal table rates', 'hash-verified escaped-underscore audit') that obscures what is actually being compared.

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?

There is a faint hint that the legacy/audit data is 'otherwise unavailable/stale', implying this is the only route to it, but there is no explicit statement of when to use this tool versus the sibling comparison tools. No exclusions, prerequisites, or alternative routing are given.

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