extract_pdf_tables

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

With no annotations supplied, the description carries the full burden and does well: it discloses that output_dir causes side effects (each table written as a CSV file, paths returned) versus in-memory CSV text otherwise, and that scanned pages are silently skipped with [] returned when nothing is found. It stops short of stating what happens to pre-existing files in output_dir or whether files are overwritten.

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?

A single front-loaded purpose sentence followed by a compact name-to-meaning list; every line carries information (formats, defaults, consequences) with no filler. The structure maps directly onto the parameters an agent must fill.

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 four-parameter extraction tool with an output schema already covering return values and no annotations to lean on, the description supplies the remaining essentials: path format, page-selection syntax, strategy tradeoffs, the on-disk side effect of output_dir, and the empty-result case. An agent could invoke it correctly without opening the schema.

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 0%, so the description must compensate fully and it does: every one of the four parameters is explained with format examples ('1,3-5' for pages), defaults, and the enumerated strategy values with their meanings. This adds substantial meaning beyond the bare typed properties 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?

States a concrete verb and resource — 'Pull the tables out of a local text PDF' — and even scopes it to text PDFs, noting that image-only pages are skipped. There are no sibling tools, so no differentiation is required, and an agent can tell immediately what this tool produces.

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?

Guidance is embedded per option: pages defaults to all when empty, and strategy lists 'lines' (ruled borders) vs 'text' (lined up by spacing), which implies when each applies. What's missing is an explicit statement of when to prefer 'auto' over forcing a strategy, or when to prefer returning CSV text versus writing files.

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