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

With no annotations, the description carries the full behavioral burden and does so thoroughly: it discloses cost (no credits), auth requirement (API key), output behavior (appear/do-not-appear with supporting excerpts), and a key limitation (field-mismatched values still read as grounded). This is exemplary transparency for a verification tool.

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 front-loaded with the core action and well organized. It is slightly longer than strictly necessary and partially restates the title, but every sentence carries meaningful semantic or behavioral information, so no sentence is wasted.

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?

Given no output schema, the description fully explains what the tool returns (which values matched, which did not, with excerpts), how to supply the source, the auth/cost profile, and the main caveat about field grounding. An agent has enough to invoke it correctly without further inference.

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 100%, so the baseline is 3. The description adds general context about how data, url, html, and text relate to each other, but does not add parameter-level detail beyond what the schema already documents. It is adequate but not additive enough to raise the score.

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 states a specific verb ('check'), resource (extracted data vs. its source page), and method (field-by-field match with excerpts). It clearly distinguishes verification from extraction/reading by saying it works on data from any source, and it explicitly separates 'is this value present' from 'does the page say this about that.'

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 gives explicit when-to-use guidance ('Use it to bound invention before you act on data you did not verify yourself') and clearly states what the tool does NOT answer. It does not name sibling alternatives directly, but it positions itself against extraction and reading tools well enough for an agent to select it.

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