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

With no annotations, the description carries the full burden, and it does disclose genuinely useful behavior: a $0.50 cost and that credentials are generated on the fly through a specific connection. However, it says nothing about branch lifecycle, credential expiry, idempotency on repeat calls, or resource cleanup — significant gaps for a provisioning/mutation tool.

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?

Two sentences, front-loaded with the cost tag and then the action. Every clause earns its place and nothing is padded.

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?

An output schema exists, so return values need not be described. Still, for a provisioning tool with zero annotation coverage and zero parameter documentation, the agent lacks essential setup context — quota impact, whether credentials expire, and whether the branch persists after creation.

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 0% for two parameters, so the description must compensate and does not — neither 'project_name' nor 'region' (with its us-east-2 default) is mentioned or explained. The agent gets no added meaning about naming constraints or regional implications beyond the raw schema.

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 names a specific verb-and-resource pair: provisioning an isolated Neon Serverless Postgres branch, further scoped to 'an external agent.' That resource is unmistakably distinct from the siblings (Cloudflare R2 bucket, stealth browser extract), so an agent can route correctly without opening any schema.

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 phrase 'for an external agent' implies a usage context and the description references the mcp-server-neon route, but there is no explicit when-to-use vs when-not, nor any alternative named. Usage is inferable rather than stated.

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