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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety is covered. The description adds useful non-annotation context: the corpus size (~200), the German-speaking scope, the data sources behind each entry (ElCom, PVGIS, subsidy programmes) and the presence of an example calculation. It does not describe pagination or result ordering, which keeps it short of 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?

A single, front-loaded sentence that leads with the core action and resource before enumerating the payload contents. It is dense but every clause carries information; only the trailing filter sentence is somewhat tacked on.

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 read-only list tool with no output schema, the description helpfully enumerates what each entry contains (price, yield, tariff, subsidies, calculation, sources), which substitutes for missing return-value documentation. Pagination and result ordering remain undocumented but are minor for a ~200-item corpus.

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 description coverage is 100%, so both parameters are fully documented in the schema with format examples ('Uster', 'ZH'). The description's 'Filter by canton or name' only restates what the schema already provides, so the baseline 3 applies.

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 ('List') and resource ('Swiss cities and municipalities') and immediately scopes it with the qualifier 'with a Soljo page', so an agent knows exactly what is returned. This is clearly distinguishable from geocode_address (address resolution) and solar_first_estimate (calculation).

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?

'Filter by canton or name' implies how to narrow results, but there is no explicit when-to-use guidance and no mention of the sibling tools as alternatives for address lookup or estimation. Usage is implied rather than stated.

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