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

The description claims 'Idempotent: calling it again returns the same database', but the annotations declare idempotentHint=false, a direct contradiction of the declared safety/retry profile. This is otherwise a rich disclosure (app restart, DATABASE_URL persisted across redeploys, DB dropped on terminate), but the explicit conflict with structured annotations is exactly the case the rubric scores at 1.

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?

Front-loaded with the action, then side effects, idempotency, alternatives, refusal condition, and lifecycle in that order. Every sentence carries distinct operational information; there is no filler or restatement of the name.

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-param provisioning tool with an output schema, it covers side effects, persistence, prerequisites, and teardown behavior. The only shortfall is that the lifecycle claim (dropped on terminate) and the idempotency claim are not reconciled with the annotations, leaving an agent unsure whether a retry has additional effects.

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?

There is a single parameter, project_id, already documented in the schema at 100% coverage. The description only implies which project is targeted ('a spawnpoint project') and adds no format, constraints, or examples beyond the schema, 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?

Opens with a specific verb+resource ('Give a spawnpoint project its own Postgres database') and immediately scopes what is provisioned and where ('created on spawnpoint's managed server'). It is clearly distinguishable from siblings like add_storage or create_upload because it names the storage type (Postgres) 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?

Explicitly states when to use it ('when the app needs real relational storage that outlives its machine') and when not to ('for a SQLite file or uploads, the persistent data directory (SPAWNPOINT_DATA_DIR) needs no call at all'). It also names a blocking prerequisite ('Refused if the user already set a DATABASE_URL of their own'), leaving nothing to inference.

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