ty_check

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the tool's safety profile is covered. The description adds the behavioral detail of an optional severity filter, but it does not disclose what `paths` or `changed_only` actually do during a check. There is no contradiction with the 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?

The description is a single, front-loaded sentence with no filler. It states the action, resource, and the key filtering option efficiently, earning every word.

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 annotations covering safety and an output schema present, the description doesn't need to explain return values. A default invocation is clear, but the lack of parameter semantics and usage guidance makes advanced use cases like `changed_only` or specific `paths` underspecified. It is adequate for a simple tool but has clear gaps.

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 description coverage is 0%, so the description needed to compensate by explaining parameters. It only hints at the severity filter (`level`) and leaves `paths` and `changed_only` unexplained. The names and defaults are somewhat self-explanatory, but the description adds little beyond what the schema already shows.

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 uses a clear verb ('Run') and names the specific resource ('ty type checking'), which distinguishes it from sibling tools like ruff_check and bandit_check. The mention of an optional severity filter also foreshadows the `level` parameter. It is clear and specific, though it doesn't explicitly contrast with any sibling.

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 implies that this tool should be used when ty type checking is needed, but it gives no explicit when-to-use or when-not-to-use guidance. No alternatives or exclusions are mentioned, so an agent must infer the usage context from the tool name and description alone.

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