Create PostgreSQL User

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

Annotations indicate readOnlyHint=false and destructiveHint=false, so the description accurately conveys a state change. However, it does not disclose other behavioral traits such as impact on existing connections, reversibility, or potential side effects. The mention of the API endpoint adds minimal context beyond the annotations.

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?

The description is three sentences long, each adding value. The first sentence restates the title (slightly redundant) but the second and third provide unique detail. No unnecessary words, but could be further streamlined by merging the first two sentences.

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?

Given the tool has 2 parameters and no output schema, the description covers the action and key effect. However, it omits important contextual details like idempotency (what if user exists?), prerequisites, and whether the operation is reversible. For a creation tool, this leaves gaps in agent understanding.

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 50% (username described, postgresId not). The description adds context by linking 'new user' to username and 'provided ID' to postgresId, partially compensating for the missing schema description. However, it does not fully clarify the format or constraints of postgresId, so baseline 3 is appropriate.

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 description explicitly states the action 'Create PostgreSQL User', the resource 'for the Render Postgres instance with the provided ID', and a key side effect: 'becomes the new default user'. This clearly distinguishes it from sibling tools like render_list_postgres_users and render_delete_postgres_user.

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 implies usage on a specific Postgres instance but does not explicitly state when to use this tool versus alternatives. It lacks prerequisites (e.g., postgres must exist, required permissions) and fails to differentiate from other postgres creation or user management tools.

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