Show table privileges

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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it is a safe read. The description adds crucial behavioral context beyond annotations: the tool is backed by information_schema.table_privileges, which postgres filters by the calling role's visibility, and a least-privileged role may miss grants. It also specifies ordering (by table then grantee) and the behavior when `table` is omitted. This is exactly the kind of behavioral disclosure that annotations alone cannot convey.

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 roughly four sentences, each carrying meaningful content: purpose, omission behavior, usage scenarios, and the visibility caveat with a recommendation. It is front-loaded with the core purpose and stays information-dense without wordiness. It could be slightly tighter (e.g., merging the usage and caveat sentences), but it is still well-structured and earns its length.

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 read-only tool with two optional parameters and an output schema present, the description covers all essential invocation context: what happens with and without `table`, the schema default, the visibility limitation, and how to get complete results. Since an output schema exists, the lack of a return-format explanation is not a gap. Nothing an agent needs in order to call this correctly or interpret the scope is missing.

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 100%, with both `table` and `schema` having descriptions. The description rephrases the omission behavior already present in the schema ('Omit to list privileges for all tables in the schema'), so it adds no new parameter-specific meaning. The only extra value is the ordering detail (by table then grantee), which is output behavior rather than parameter semantics. Thus 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 clearly states the verb/resource (shows roles and their privileges) and enumerates the specific privilege types (SELECT, INSERT, etc.). It distinguishes itself from sibling tools (e.g., pg_list_tables, pg_describe_table) by focusing exclusively on privilege grants. It also provides a concrete use question ('who can write to this table?'), which removes any ambiguity about the tool's intent.

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 identifies when to use this tool: to answer 'who can write to this table?' or to audit schema-wide access before a migration. It also advises running as a superuser for a complete picture, which is a practical usage hint. However, it does not name alternatives or state when *not* to use it, so it lacks explicit exclusions. This fits the 'clear context, no exclusions' benchmark.

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