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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that the result is a count-per-place projection of the person's own job data, but says nothing about failure modes, empty results, or how the numbers are keyed.

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?

Purpose is front-loaded in the first clause, and the two parameter sentences are dense but each carries real information. The single run-on sentence is slightly harder to parse than it needs to be, but there is no filler.

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 two-parameter, no-output-schema tool, the description covers the default level and the level/place dependency, which is what an agent needs to invoke it correctly. What the returned counts are keyed by (place names vs codes) is left implicit, which is the main remaining gap.

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 100%, so the baseline is 3, but the description goes beyond the schema's terse field notes by explaining the hierarchy: `place` narrows to 'the place one level up', with concrete examples (a country ISO code to count by region, a province to count by city). That relational rule is genuinely useful and not derivable from the schema alone.

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 (count) and resource (the person's jobs) with an explicit scope (per place), and the phrase 'the numbers on the map' conveys the aggregation intent well enough to separate it from search_jobs. It never names a sibling as the alternative though, so differentiation is inferred rather than stated.

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?

Usage is implied rather than prescribed: the agent can infer this is for aggregate counts rather than listing individual jobs, and the default ('country by default') is given. There is no explicit 'use this when you want totals, use search_jobs when you want the jobs themselves' routing.

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