find_elements_count

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 clearly states the core read-only behavior, but it does not mention whether hidden elements are counted, whether it waits for elements to appear, or how invalid selectors are handled.

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 sentence with no filler or repetition. The key action and target are front-loaded and immediately understandable.

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 simple one-parameter counting tool with an output schema, the description provides sufficient information to understand the tool's purpose and invoke it correctly. Minor gaps remain around edge-case behavior and usage context, but these do not undermine the core operation.

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 only defines 'selector' as a plain string with 0% description coverage. The description adds meaning by specifying that the selector is a CSS selector used to match elements on the page, which compensates for the schema's lack of detail.

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 specific verb ('Count') and a clear resource ('elements on the page match a CSS selector'). It clearly distinguishes itself from sibling tools like click, get_text, or is_element_visible by focusing solely on counting matching elements.

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?

No guidance is provided about when to use this tool versus alternatives such as is_element_visible or wait_for_element. The usage context is only implied by the tool's function, and no exclusions or alternative routing are mentioned.

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