Lookup Values

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the agent knows the safety profile. The description adds the behavioral purpose of grounding literals but says nothing about whether values are distinct, how they are ranked, or how limit truncation behaves. With annotations and an output schema covering most of the surface, a 3 is appropriate.

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?

A single sentence that front-loads what the tool returns and follows with the use case and concrete examples. Every clause earns its place with no filler.

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?

Output schema, complete parameter docs, and safety annotations are all present, so the description only needs to convey intent and usage, which it does. The one gap is that it does not mention the common-value ordering or the multi-datasource requirement, both of which an agent would need to consult the schema for.

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 all four parameters are fully documented in the schema, including the 'table.column' format and the contains/limit behavior. The description adds intent (grounding filters) but no additional format or constraint detail beyond the schema, so it sits at the baseline.

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 states a specific resource (real values stored in a column) and its purpose (grounding literal filters). The examples ('Pennsylvania', product name, status code) make the output concrete. It does not explicitly distinguish itself from siblings like describe_table or get_term, which also describe column contents, so it falls short of a 5.

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?

It gives clear temporal guidance: call this before writing literals into SQL. That establishes when to use it. There is no explicit when-not guidance or named alternatives (e.g., use describe_table to get the column type instead), which keeps it at 4.

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