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

The description adds substantial behavioral context beyond the annotations: credit cost per started 10 pages, a 100-page cap, 10-minute output expiry, and potential digital signature invalidation. This goes well beyond the minimal readOnly/destructive hints and gives the agent important operational expectations.

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 compact and front-loaded: the purpose appears first, followed by concise, non-redundant sentences about limitations, cost, expiry, and side effects. Every sentence adds distinct value, with no filler or repetition.

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 tool with 7 parameters, no output schema, and only 14% schema description coverage, the description is incomplete. Critical semantics for 'degrees' and 'pages' are absent, and the 'one PDF' phrase conflicts with the array of up to 10 fileIds. The cost and expiry details are helpful, but not sufficient for confident invocation.

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 14%, so the description must compensate, but it only reuses the names title, author, and subject. It fails to explain 'degrees' (rotation), the meaning of 'pages', or how fileIds relates to the stated 'one PDF' scope. It does add a page-limit and cost constraint, but that is not enough to clarify the undocumented parameters.

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 identifies a specific action and resource: 'Set title, author or subject on one PDF.' It also distinguishes itself by explicitly stating it is not redaction or metadata sanitization. However, it omits the rotation-related 'degrees' parameter and says 'one PDF' while fileIds allows up to 10, so scope is not fully accurate.

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 gives an implied usage by naming the metadata fields, and it provides one when-not instruction: 'This is not redaction or complete metadata sanitization.' It does not explicitly route to alternatives or explain when to prefer pdf_rotate, pdf_extract, or other sibling tools, but the core use case is inferable.

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