describe_postgres_schema

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

With no annotations, the description carries the full burden. It describes the return structure and warns about large schemas, but does not explicitly state read-only nature, required permissions, or error handling. The word 'Inspect' implies read-only, but more explicit disclosure would improve transparency.

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 concise (about 100 words) and front-loaded with purpose. It uses bullet-style formatting for the return structure. There is no unnecessary verbosity, but it could be slightly tighter by condensing the usage advice.

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's simplicity and the presence of an output schema, the description covers key aspects: purpose, when to use, return format, and large schema handling. Minor gaps include not specifying behavior for nonexistent schemas or error conditions.

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 high (both parameters have descriptions in the schema), so baseline is 3. The tool description does not mention parameters or provide additional semantics beyond what the schema already offers.

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 'Inspect a PostgreSQL schema and return its full structure as JSON'. It differentiates from sibling tools like execute_postgres (execution), explain_postgres (query plan), list_projects (project listing), and pg_stat_statements (statistics), all of which have distinct purposes.

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 advises 'Call this before writing any query, JOIN, or EXPLAIN — it gives you exact table/column names and indexes so you don't guess'. It also recommends filtering client-side for large schemas, though it doesn't explicitly state when not to use or list alternatives.

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