pdf_info

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the cost ($0.01), the local-path input constraint, and the lightweight/cheap nature of the call. It does not say what happens on encrypted or malformed PDFs, nor whether the metadata call fails or degrades, leaving a real gap for a read tool with zero annotation coverage.

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?

One tight sentence that front-loads the verb and resource, then the field list, then the cost. Every clause earns its place 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?

No output schema exists, and the description enumerates the returned fields adequately for an agent to know what comes back. The local-path constraint and cost cover the main call-time decisions; only error/encryption-edge behavior is absent.

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 0% and the single 'file' parameter is undocumented in the schema. The description compensates by specifying '(local path)', which tells the agent this is a filesystem path rather than a URL or ID — meaningful semantics beyond the bare string type.

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?

Specific verb (read) plus resource (PDF metadata) with an explicit enumeration of the returned fields (page count, title, author, PDF version, page size, encryption and form flags). It is clearly distinguishable from siblings like image_info, render, or pdf_merge, which act on content rather than metadata.

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?

States the usage context plainly: 'a cheap first check before more expensive processing,' which tells the agent to probe with this before invoking heavier siblings like pdf_to_images or ocr. It does not name those alternatives or state exclusions, so it falls short of a full 5.

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