variable_completions

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool returns matches based on a prefix and mentions 'orderless', hinting at a fuzzy or flexible matching approach, but lacks details on permissions, rate limits, output format, or error handling, leaving significant gaps for a tool that queries variables.

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 a single, efficient sentence that directly states the tool's function without unnecessary words. It is appropriately sized for a simple query tool, though it could be more front-loaded with key details like output format or sibling differentiation to improve clarity.

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?

Given the lack of annotations and output schema, the description is incomplete. It does not explain what the return values look like (e.g., list format, data structure), error conditions, or how 'orderless' affects matching, making it inadequate for an agent to fully understand the tool's behavior in context with its siblings.

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 description coverage is 100%, with the parameter 'variable_prefix' clearly documented in the schema. The description adds minimal value by restating the prefix matching concept but does not provide additional syntax, examples, or constraints beyond what the schema already specifies, aligning with the baseline for high schema coverage.

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 action ('Return all variables matching a prefix') and the resource ('variables'), making the purpose understandable. However, it does not explicitly differentiate from sibling tools like 'variable_documentation' or 'variable_source', which also operate on variables, leaving some ambiguity about when to choose this specific tool.

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 provides no guidance on when to use this tool versus alternatives, such as 'variable_documentation' or 'variable_source'. It mentions 'using orderless', which might imply a specific matching behavior, but does not clarify context, prerequisites, or exclusions, offering minimal usage direction.

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