pdf_metadata

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

With no annotations provided, the description carries the full burden. It discloses the dual-storage nature (Info vs XMP), the normalized output with sources and conflicts, and the presence of has_conflicts. It even instructs the agent on how to behave when conflicts exist, which is beyond typical transparency.

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 well-structured: a clear purpose sentence, a negative definition that routes to alternatives, a detailed but necessary explanation of the output behavior, and a final args block. It is efficient and front-loads the most important information without fluff.

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 tool's complexity (metadata conflicts) and the existence of an output schema, the description still adds critical context about how to interpret the returned data (sources, conflicts, has_conflicts). It covers what the tool returns, how conflicts are resolved, and the dual stores. Nothing an agent needs to call it correctly is missing.

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 only parameter ref is explained as 'PDF file path, or a workspace artifact id.' This adds semantic meaning beyond the schema's bare 'string' type. Since schema coverage is 0%, this explanation fully compensates for the absence of parameter descriptions in the schema.

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 opens with a specific verb and resource: 'Read a PDF's document properties: title, author, dates, producer, keywords.' It clearly distinguishes itself from siblings by naming pdf_page_count and pdf_check_text as alternatives for different tasks, so an agent can immediately tell what this tool does and what it does not.

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 explicitly states when NOT to use this tool: 'It does not count pages (use pdf_page_count) and says nothing about whether the pages hold readable text (use pdf_check_text).' It also gives operational guidance on how to handle conflicting metadata, advising to report has_conflicts rather than quoting a single value as fact. This covers both exclusions and usage context.

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