validate_selectors

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

With no annotations, the description must bear the full burden of behavioral disclosure. It only says 'validate' and 'check reliability,' but does not state whether it tests against the current page, requires a loaded page, makes network requests, or has any side effects. This leaves agents uncertain about prerequisites and consequences.

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, short sentence with no filler or redundancy. It states the core action directly and is appropriately front-loaded, making it highly concise and effortless to parse.

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?

The tool is relatively simple, but the description lacks essential context: it doesn't explain what 'reliability' means, what the output is, or any prerequisites (e.g., a page must be loaded). With no annotations and no output schema, this minimal description leaves significant gaps for effective invocation.

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 100% (both url and selectors are described). The description adds no additional parameter semantics beyond what the schema provides, so a baseline score of 3 is appropriate.

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: 'Validate existing selectors and check their reliability.' The verb 'validate' and resource 'existing selectors' make it specific. While it distinguishes from siblings like generate_selectors (which creates new selectors), it does not explicitly differentiate from test_extraction, so it earns a 4 rather than a 5.

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 usage for existing selectors ('Validate existing selectors'), but provides no explicit guidance on when to use this tool versus siblings like test_extraction or inspect_field_manually. No alternatives or exclusions are mentioned, only an implied context.

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