merge

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

No annotations are provided, so the description must convey behavioral traits. It only mentions that pages are preserved in order, but does not disclose whether input files are modified, whether the output file is overwritten, if permissions are required, or what the tool returns. This is a significant gap for a tool that creates a new file.

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 concise sentences that immediately state the action and a key constraint. There is no redundant or misleading information, and every word earns its place.

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 simple with only 2 parameters, and the schema fully covers them. However, with no output schema and no annotations, the description does not explain return values or input-file safety, leaving some contextual gaps. It is adequate for the core function but lacks complete behavioral context.

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 'files' and 'output_name' have clear descriptions. The tool description adds no additional parameter semantics beyond what the schema already states, so the 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 verb ('Combine') and resource ('multiple PDF files') and specifies the outcome ('into a single document'). It also distinguishes itself from sibling tools like 'alternate_merge' by noting 'Preserves all pages in order', implying a sequential merge rather than interleaving.

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: when multiple PDFs need to be combined into one document. However, it does not explicitly mention alternatives or exclusions (e.g., when to use alternate_merge instead), so it falls short of a 5.

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