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

With no annotations, the description carries the full burden. It discloses that the tool 'Runs in the browser' and details credit/pricing coverage, which are useful behavioral context. However, it does not disclose whether the tool is interactive, what it returns, or how it handles PDF inputs, leaving significant behavioral ambiguities.

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 purpose in the first sentence, making it immediately clear what the tool does. The subsequent sentences about browser execution and billing are somewhat wordy and less core to the tool's function, but they are not overly long and add useful context. Overall, it is structured effectively without excessive verbosity.

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?

Despite having no parameters or output schema, the description fails to explain how an agent should invoke the tool or what happens after invocation. It does not mention that the tool likely opens an interactive browser editor, requires user interaction, or produces any output. The billing details do not compensate for the lack of operational guidance, leaving the description incomplete for an AI agent.

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 input schema has zero parameters, so there are no parameter details to document. The baseline for 0 params is 4, and the description does not need to add parameter meaning. It does hint at the tool being a browser-based editor, which is sufficient given the empty schema.

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 'Edit PDFs: add text, mask content, annotate, OCR' which is a specific verb and resource, clearly distinguishing it from sibling PDF conversion and manipulation tools. The capabilities are enumerated, making the tool's core function unambiguous and differentiation from PDF merge/compress/split tools evident.

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 scenarios by listing editing operations (add text, mask, annotate, OCR), but it does not explicitly state when to use this tool over alternatives or provide exclusions. It mentions 'Runs in the browser' but does not clarify when this is preferable to other PDF tools, leaving the guidance implicit rather than explicit.

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