Images to PDF

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

With annotations already declaring readOnlyHint=false and non-destructive/idempotent flags, the description adds a genuinely useful trait beyond structured data: it runs entirely locally and never transmits files. It does not, however, explain what happens when the output path already exists (the 'force' contract) or how failures surface, so it stops short of full behavioral coverage.

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?

Two sentences, front-loaded with the core action and ordering rule, second sentence carrying the privacy guarantee. No filler or redundancy.

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 straightforward creation tool with full schema coverage, annotations for the safety profile, and no output schema, the description covers what the agent needs. Minor gap: it does not mention overwrite behavior or the default page size, though the latter is caught by the schema.

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%, so all four parameters (inputs, output, pageSize enum, force) are already documented in the schema. The description only restates the ordering semantics of 'inputs' that the schema already conveys, adding no new syntax or format detail. Baseline 3 applies.

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?

Names a specific verb ('Build a PDF') and resource ('from PNG and/or JPEG images'), plus the exact layout contract ('one image per page, in the order given'). This is clearly distinguishable from every sibling, all of which manipulate existing PDFs rather than create one from images.

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?

Usage is implied by the input types (you have images, you want a PDF), but the description never states when to prefer this over alternatives such as pdf_merge (combining existing PDFs) or when not to use it. No prerequisites or exclusions are given.

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