list_env_var_values

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

Discloses that it returns distinct values across test runs, but with no annotations, the description should also mention any side effects or response format. It adequately describes behavior for a simple read tool.

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?

Three sentences: first states purpose, second gives prerequisite, third provides use case. No redundant 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?

Lacks explicit response format (e.g., array of strings) and error cases, but for a simple tool with one parameter and no output schema, it covers the essential context.

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 covers the parameter fully (100% coverage). The description reinforces the parameter's origin from list_env_vars but adds no new semantic details beyond the schema.

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 it lists recorded values for a specific environment variable key, with an example (browser versions). It distinguishes itself from siblings like list_env_vars (which lists keys) and suggest_env_var_values.

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 instructs to use envVarId from list_env_vars and highlights usefulness for building AQL filters. It implies when to use but does not explicitly state when not to.

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