get_metadata

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

Annotations already cover the safe, read-only, idempotent nature of the call. The description adds meaningful behavior beyond that, especially the special case where password-protected documents return only 'encrypted: true' and 'needs_password: true'.

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 front-loaded with a clear purpose and then moves into useful field semantics. It is somewhat longer than necessary because an output schema already exists, but the field-specific details such as 'pages_needing_vision' and encryption behavior earn most of the space.

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 simple one-parameter metadata tool with annotations and an output schema, the description is complete enough to call correctly. It covers the required path semantics and the important encrypted-document edge case.

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 input schema has 0% description coverage, and the description fully compensates by explaining that 'path' is the PDF's absolute path on the local machine. This is the only parameter and its key constraint is stated clearly.

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 clearly defines the tool as returning metadata about a local PDF before reading/extracting it, and the field list makes the resource scope concrete. It distinguishes the tool from extraction siblings by framing it as a pre-read inspection step.

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 phrase 'before reading it' implies when to use the tool, but no sibling alternatives are named and there are no explicit when-not-to-use conditions. The guidance is inferable rather than stated.

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