Wait For Selector

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

Beyond the annotations (readOnly, non-destructive), the description discloses the return value ({ ok: true }), the timeout behavior ('Throws a timeout error naming the selector and state'), and default values for state and timeoutMs. This gives the agent a clear model of runtime 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 well-structured: a summary sentence, Args list, Returns, an Example, and Error Handling. Every section is concise and directly useful, with no filler.

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 wait tool with 7 params and an output schema, the description covers all essential aspects: purpose, args, return value, timeout error behavior, and a usage example. It is complete and self-contained for an agent to invoke correctly.

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 coverage is only 57%, and the description compensates by explaining the key parameters: selector, state, and timeoutMs, including defaults and the meaning of tab filters. It adds meaning beyond the schema without repeating every schema field 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 begins with a clear, specific statement: 'Waits until a selector reaches a given state, or times out.' This identifies the exact verb+resource and the tool's purpose, distinguishing it from sibling action tools like click or type.

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?

It provides a concrete 'Use when' example ('wait for the spinner to disappear before continuing') and explains tab selection via optional args. It lacks explicit exclusions or alternative tool comparisons, so it falls short of a 5.

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