Add page labels

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

With annotations already declaring readOnlyHint=false, idempotentHint=true, and destructiveHint=false, the safety profile is covered by structured data. The description adds nothing behavioral beyond that: it does not say the result is written to a new file, that output must not already exist, or that input/paths are restricted to allowed folders – all of which live only in the schema.

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, no filler, and the core capability is front-loaded before the syntax hint. Nothing in the text is redundant with the name or title in a wasteful way.

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?

An output schema exists, so return values need not be described, and annotations carry the safety profile. Still, for a file-mutating tool with five parameters, the description omits placement defaults, the omit-pages-means-all-pages rule, and any sibling routing, leaving it only minimally adequate.

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 80%, so baseline is 3, but the description genuinely compensates for the one gap: the 'text' property has no schema description, and the description supplies the {page} and {total} placeholder syntax. That is real value beyond the schema for a parameter an agent would otherwise have to guess at.

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 and outcome: 'Add page numbers or a footer'. That is clearer than the title alone and tells the agent it stamps text onto pages. It does not, however, distinguish itself from near siblings like pdf_add_watermark or pdf_add_text, which perform visually similar stamping operations.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as pdf_add_watermark or pdf_add_text. The only guidance offered ('Use {page} and {total} in the text') is syntax help for one parameter rather than tool-selection advice.

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