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

Annotations already declare readOnly=true, destructive=false, so the safety profile is covered. The description adds the ADMIN-ONLY access constraint and previews what each row contains — meaningful context beyond the structured fields.

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?

One dense sentence plus a short param note; the scope and purpose are front-loaded before the detail list. Slightly list-heavy but every clause contributes information.

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?

With no output schema, the description usefully enumerates what the tool returns, and the admin-only restriction is disclosed. Adequate for a one-param read tool; only pagination/ordering behavior is unaddressed.

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 coverage is 100% with a single optional limit parameter, so the schema already carries the meaning. The description restates the default and max but omits the schema's lower bound of 5; it adds essentially no semantics beyond the schema, so baseline 3 applies.

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?

States a specific verb and resource — database size broken down by table — and enumerates the exact outputs (heap/index/TOAST split, live/dead rows, retention). No sibling covers storage, so differentiation is implicit but the scope is unmistakable.

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 frames the use case: 'what is filling the database' and the intent to run it before choosing retention. Gives clear context but names no alternative tool for the same question, so no true when-not guidance.

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