What this server can and cannot do

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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds context by stating the tool asks PostgreSQL rather than assuming, enumerates the specific checks performed, and reveals that it returns a grade plus fix commands. It also advises acting on alarming results. This goes beyond the annotations without contradicting them.

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 two sentences with no fluff. It front-loads the purpose, lists specific checks in a compact list, then states the output format and usage recommendation. Every clause adds value, making it appropriately sized for a security audit tool.

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?

Despite lacking an output schema, the description explains the return value (a grade and fix commands) and covers all relevant behavioral aspects. It also provides a usage context (session start) and what to do with results. For a tool with one optional parameter, this is complete and self-sufficient.

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?

The input schema has 100% coverage with a single optional 'database' parameter described as 'which configured database to use; omit when only one is configured.' The description does not add parameter-specific details, but the schema already fully covers it, meeting the baseline for schema-heavy tools.

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 clearly states the tool assesses the deployment's actual capabilities against the database (write, RLS bypass, file access, auth, encryption) and returns a grade with fix commands. It distinguishes itself from sibling tools like database_health and query by being a session-start security audit rather than a data operation. The verb is specific and the resource (security posture) is well defined.

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 explicitly recommends calling this tool once at the start of a session and instructs the agent to communicate alarming results to the user. It does not explicitly mention alternatives, but given sibling tools, the context is clear. The guidance is useful and actionable, though not exhaustive on when not to use it.

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