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 explicitly states 'Read-only: it never touches your repo' and clarifies that it is a heuristic text scan, not a structural guarantee. This gives the agent confidence about side effects and limitations, though it does not disclose output format or error behavior.

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 three sentences with no filler. It front-loads the purpose and output, then adds the read-only guarantee and heuristic limitation. Every sentence earns its place, and the structure makes the tool's behavior easy to absorb.

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?

For a one-parameter tool with no output schema, the description provides enough context: what to pass, what problems are detected, that it is read-only, and that it is heuristic. The only minor gap is that the exact return format is not specified, but the listed problem categories make the expected output sufficiently clear.

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 already describes the single 'code' parameter as 'the TSX snippet to check,' and schema coverage is 100%. The description adds meaningful context by specifying that the TSX should use 'these components' and that the result is a list of glass-safety problems, which helps the agent understand what input to provide beyond the bare schema description.

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 tool's purpose with a specific verb and resource: paste TSX and get back glass-safety problems. It lists concrete issue categories (animated opacity, flex:1 collapse, clipped lens, conditional mount), which makes the tool's output expectations unambiguous and distinguishes it from the sibling get/find/list tools.

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 makes the primary use case clear: use this tool when you have a TSX snippet and want to check it for glass-safety problems. It also provides a boundary by stating it is a heuristic text scan, not a structural guarantee, which helps the agent decide whether this tool is appropriate. It does not explicitly name alternatives, but the context is sufficient.

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