lookup_building

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the incremental bar is low. The description adds the live-API behavior ('always current, no dump download needed') and explains the EGID's role as a join key, which is useful beyond the schema.

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?

Three short sentences, no filler; purpose is front-loaded in the first sentence and the remaining sentences each add one relevant fact (live API, EGID role).

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 one-parameter, read-only lookup with an output schema, the description is nearly complete: it states the resource, the identifier semantics, and data source. It could optionally mention routing to siblings (e.g., use address_to_egid when no EGID is known), but that gap is minor for this simple tool.

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% and the schema only names the property 'egid' with type integer. The description defines EGID as a federal building identifier and the cross-administrative join key, adding the missing semantic meaning, though it stops short of providing an example or value-format details.

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 opening sentence states a specific action and resource: 'Look up a single building by its EGID (federal building identifier).' The qualifier 'single building' plus EGID distinguishes it from siblings like buildings_in_bbox and address_to_egid, so a user can select it correctly.

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 gives clear context: it should be used for exact EGID lookups against the live geo.admin.ch API, and it explicitly avoids needing a dump download. It doesn't name sibling alternatives or state exclusions, but the 'single building by EGID' phrasing implies the boundary.

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