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

No annotations are supplied, so the description bears the full burden. It discloses one genuine behavioral trait (limited, non-parser formatting that may not handle complex SQL), but says nothing about input expectations, whether the query is echoed back, error behavior, or size limits.

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?

Two sentences, purpose first and the limitation second, with no filler. Every clause contributes; a slightly more explicit input hint could be added without bloat.

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 trivial tool this is close, but with an untyped body schema and no output schema, the description should state how the SQL is supplied and what comes back. Neither is covered, so an agent must infer the entire call contract.

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 schema declares a free-form POST body with additionalProperties and no named properties, so the agent gets no field names from the schema either. The description does not describe the request body shape at all, leaving the caller to guess how the query is passed despite zero declared parameters.

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?

"Pretty-print a SQL query" gives a specific verb plus resource, and the follow-up sentence narrows the tool's class. It does not name a sibling such as json_format or xml_json to distinguish scope explicitly, but the resource (SQL) makes the boundary obvious.

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 caveat "lightweight formatter, not a full SQL parser" implies when the tool is appropriate and warns of failure on complex dialects, which is real guidance. There is no explicit when-to-use/when-not framing or pointer to an alternative path for full parsing.

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