Split a local PDF

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

Goes well past what the annotations declare: it names the write target (a new directory), discloses a hidden cost (reopening every output PDF to count pages), and enumerates losses (tags, labels, attachments, metadata, unsupported actions) plus signature invalidation. 'Writes a new directory' is consistent with destructiveHint=false since no existing data is claimed to be removed, so no contradiction arises.

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?

Three sentences with the operation, the output shape, and the side effects ordered by importance; no filler and no restatement of the title. The dense phrasing still resolves into distinct facts.

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 6-parameter mutation tool with no output schema and only partial schema documentation, the description covers preconditions, side effects, and data loss adequately. It stops short of describing the created directory's structure/naming or error behavior, and leaves two optional parameters unaddressed.

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 only 33%, and the description compensates partially by explaining the mode enum semantics (each page / batches / explicit ranges) and that ranges are 1-based, which the schema does not say. But keep_bookmarks and pages_per_file are left entirely unexplained, and the blanket 'omits metadata' sits awkwardly against a keep_bookmarks default of true, leaving the agent to guess their interaction.

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?

States a specific verb (split) against a specific resource (an unencrypted local PDF) and enumerates the three output shapes (per page, batches, range groups). The scope 'local, unencrypted' plus 'writes a new directory' cleanly separates it from the sibling image/EXIF utilities and from any in-place PDF operation.

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 constraints 'unencrypted' and 'local' function as implicit preconditions, telling the agent when this tool will refuse work. However, there is no explicit when-to-use guidance, no statement about when to prefer batches over ranges, and no mention of alternatives; the agent must infer invocation conditions from the description.

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