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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive write. The description adds value beyond that: the required write scope and a cross-field validation rule (paired lat/long, one without the other is rejected) that would otherwise only surface as a runtime error.

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, front-loaded with the action, then the prerequisite, then the one non-obvious constraint. Nothing is padded and every sentence carries 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 create tool with no output schema, the description covers the action, the auth scope, and the key data-integrity constraint. It omits any note on required parent entities (e.g. that site_id must reference an existing site) or failure behavior, but nothing essential to calling it correctly 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?

Schema description coverage is 100%, so all nine parameters are documented in the schema, giving a baseline of 3. The description's lat/long pairing note duplicates what the schema already states in each parameter's description, so it adds no new semantic detail.

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+resource ("Create a new building") which is immediately clear. However, it does no work to distinguish itself from the many sibling create_* tools, notably create_project_building and create_site, so an agent must infer which entity is which from the name alone.

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?

It surfaces a real precondition ("Requires buildings:write scope"), which tells the agent about an authorization gate. But it gives no guidance on when to use this versus create_project_building or create_site, and no exclusions, leaving usage largely implied.

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