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

Annotations only declare readOnlyHint=true, so the description carries real weight and delivers it: auto-added LIMIT, inaccessible credential tables, meta_key requirement, [redacted] values, refusal of comments/multiple statements, SHOW whitelist, and a 10s timeout. It stops short of describing the result shape, but the output schema covers that.

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?

Front-loads the read-only statement types and constraints in a single dense paragraph with zero filler. It is packed tightly, but each clause (redaction, timeout, SHOW whitelist, list-* preference) earns its place.

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 query tool with a rich output schema, the description covers safety, syntax restrictions, sensitive-data handling, timeout, and routing to siblings. Nothing an agent needs to call it correctly 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 coverage is 100%, so the sql and limit parameters are already documented. The description adds only marginal param-level detail (that a LIMIT is auto-added, and the meta_key pairing rule), which is the baseline-3 territory when the schema does the heavy lifting.

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 (execute read-only SQL to investigate what the site holds: counts, content, meta keys) and explicitly routes away from generic use toward the list-* siblings. An agent can distinguish it from every list-* and get-* tool without opening the 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?

Gives explicit when-to-use (investigate counts/content/meta keys) and when-not ('Prefer the dedicated list-* tools where one exists; never a substitute for a write'), naming both the alternative tools and the excluded use case. Nothing is left to inference.

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