list_execution_providers

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

With no annotations, the description carries the full burden. It transparently explains what the `ready`/`strict` fields mean (resolution facts, not execution-tested) and what they do not mean, which is crucial for interpreting the output. It does not explicitly state that the operation is read-only or describe potential side effects, but the listing nature implies no mutation, and the focus on output semantics is a strong, relevant disclosure.

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 longer than a single sentence but each part earns its place. It front-loads the purpose, then adds a clarifying paragraph that prevents a common misinterpretation. The structure is logical and the detail is justified by the domain's ambiguity, though it could be trimmed slightly without losing critical 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?

Given the tool has an output schema (though not provided here), the description correctly avoids repeating return structures and instead explains the semantic meaning of key fields. It also references sibling tools for complementary information, closing the loop on what the user should look at for language reliability. Nothing essential is missing for a zero-parameter listing tool.

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 tool takes zero parameters, so the description adds no extra meaning to parameter values—there are none to document. Per the baseline, this earns a 4. The description focuses entirely on output interpretation, which is appropriate for a parameterless listing tool.

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 opens with a precise verb+resource: 'List execution providers (execution BACKENDS — local subprocess, gVisor-strict, remote) and their machine-readable capabilities.' It immediately clarifies the core concept and sets it apart from language concerns. The explicit contrast with 'not which LANGUAGE' and the references to list_languages/runtimes_status make the tool's unique position unmistakable.

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 gives explicit when-to-use guidance: for backend capabilities, not language reliability. It explicitly says per-language reliability is 'a separate axis reported by list_languages/runtimes_status/codecalc doctor as tier' and warns that 'a ready provider says nothing about whether a specific language running through it has ever been execution-tested.' This tells an agent exactly when to pick this tool over its siblings and what it must not use it for.

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