Selector health check

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds no contradiction. It goes beyond annotations by explaining the significance of a degraded strategy and clarifying that the tool reports fallback/missed statuses, which is useful behavioral context for interpreting results.

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 two sentences long, directly states the tool's purpose in the first sentence, and adds a concise explanatory note in the second. Every word earns its place; there is no fluff or repetition.

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 read-only, zero-parameter diagnostic tool with no output schema, the description is complete: it defines what is reported, the meaning of different statuses, and the significance for users. Nothing essential is missing.

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 tool has zero parameters, so the baseline is 4. The description does not need to explain parameter semantics, and it appropriately focuses on behavioral output rather than input details.

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 what the tool does: it reports which Facebook DOM strategies have been matching, fallen back, or missed. This is a specific verb ('Report') with a clear resource ('Facebook DOM strategies') and scope (matching/fallback/missed), distinguishing it from sibling tools that perform actions like reading, posting, or searching.

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 provides clear context for when to use the tool: as an early warning for Facebook markup changes. It explains that a degraded strategy indicates extraction works but on a brittle fallback. It does not explicitly name alternative tools or state when not to use it, but the context is strong enough to guide the agent.

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