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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false. Beyond those, the description adds two genuinely useful behavioral facts: the required buildings:write scope and the coordinate pairing/clearing rule. It does not explain what a destructive update does to unspecified fields, but it meaningfully exceeds the annotation baseline.

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 tight sentences, front-loaded with the action and ID, then the permission requirement, then the trickiest constraint. Every sentence carries distinct, non-repeated information.

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 10-parameter mutation tool with full schema coverage and annotations covering the safety profile, the description supplies the missing operational context (auth scope, coordinate constraint). No output schema exists, but return values for an update are not critical to correct invocation.

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 the baseline is 3. The description adds meaning beyond the schema by specifying the null-clearing recipe for latitude/longitude, which the schema documents only as a pairing requirement. Minor redundancy on the pairing rule keeps it from a 5.

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 and resource ('Update an existing building') and identifies the key selector ('by ID'). It is clearly distinguishable from update_building_type or update_site, though it does not name those siblings explicitly.

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 by 'existing building by ID' and the scope requirement, but there is no explicit when-to-use guidance, no mention of partial-update semantics, and no routing to alternatives like update_building_type when the type rather than the building is the target.

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