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

Discloses that the operation creates a new job_id with a parent_job_id linking to the source, exceeding the baseline set by annotations. It also indicates that the result should be viewed via view_pdf, adding behavioral context not present in annotations.

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 three sentences, front-loading the primary action, then adding critical usage notes and an exclusion. Every sentence is purposeful and concise, with no filler.

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 the availability of annotations and an output schema, the description covers the tool's purpose, preconditions, post-operation steps, and distinction from related tools. It is complete for the tool's complexity without redundant details.

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 already provides 100% parameter coverage with clear descriptions for all four parameters. The description does not add significant meaning beyond the schema, 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 tool's function ('Add password protection to an unprotected PDF file') and distinguishes it from the sibling tool change_password by explicitly noting when not to use it. This meets the highest standard for purpose clarity.

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?

Provides explicit usage guidance: do not call on already-protected PDFs, use change_password instead, and instructs to call view_pdf with the new job_id after completion. This fully addresses when and when not to use the tool.

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