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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint true-family, so the description's 'Read-only and non-destructive' only reinforces them. The added value is the disclosed return shape: supported_languages and support_progress with ranked target counts, progress fraction, and label. No contradictions with annotations.

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, each serving a distinct purpose: scope, safety/usage, and output. It is front-loaded with the verb and resource, avoids filler, and every sentence earns its place.

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?

With no input parameters and no output schema, the description provides everything the agent needs: what the tool lists, the ranking semantics, and the exact output fields. The workflow hint about create_repository_snapshot completes the 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?

The tool has zero parameters and schema coverage is 100%, so there are no parameter descriptions missing. The description adds no parameter semantics but instead specifies the output contract, which is the relevant contextual information. Baseline 4 for a no-parameter 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 the explicit verb 'List,' identifies the resource ('globally supported Repository Intelligence languages'), and clarifies that it returns 'ranked support progress.' This is specific enough to distinguish it from generic capability-listing siblings like list_capabilities or list_runtime_libraries.

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 directs the agent to call this tool before create_repository_snapshot, a concrete when-to-use workflow with a named sibling. It doesn't enumerate when not to use alternatives, but the clear precondition provides sufficient context.

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