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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful context beyond that: counts are computed over the whole register, are published figures not sums of search results, and each figure includes scope, period, and definition. This helps set correct expectations for the agent.

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?

The description is somewhat dense but every sentence contributes useful information: the question answered, the list of figures, the metadata carried, the computation method, and the lack of arguments. It is front-loaded with the main purpose and does not waste words, though it could be tightened slightly.

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?

For a no-argument, read-only tool with full schema coverage and no output schema, the description is remarkably complete. It tells the agent what figures will be present, their scope/period/definition, and clarifies that totals are register-wide published numbers rather than search-derived sums. Nothing essential is missing.

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, and the description states 'Takes no arguments,' matching the schema coverage of 100%. Per the rubric, a 0-parameter tool gets a baseline of 4, and no additional semantic detail is needed.

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 clearly answers a specific question ('how many jobs has AI replaced...') with a specific resource (the register's published count), and distinguishes itself from siblings that fetch indexes, company-level details, or search events. It enumerates the exact figures returned, leaving no ambiguity about the tool's function.

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 description states the exact question this tool answers, which implicitly defines when to use it. It does not mention alternatives or exclusions, but the context is clear enough for an agent to select it for aggregate count queries. A 5 would require explicit sibling routing, which is absent.

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