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

Annotations already signal read-only/non-destructive behavior; the description adds useful transparency by listing the exact returned fields and revealing that ExternalKey is an internal GUID. It also clarifies path format and source, which are behavioral context not present in annotations. No contradiction.

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?

Three short sentences: the first states the operation, the second enumerates returned fields, and the third explains path provenance. Every sentence earns its place and there is no padding.

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 single-parameter read-only metadata lookup, the description is complete: it names the required input format, gives examples, and lists the return fields, compensating for the missing output schema. It does not need to explain error behavior for this simple operation.

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 100%, and both the schema and description give the same leading-slash '/photos/logo.jpg' examples. The description adds the source (File-type field value) but largely reinforces, rather than extends, 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?

Description opens with a specific verb and resource: 'Returns metadata for a file in Caspio's file system' and names the key fields returned, including ExternalKey. This makes the tool's scope clear and separates it from general search/discovery siblings, even without naming get_attachment_metadata explicitly.

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?

It gives concrete guidance on input provenance: the file path must come from a File-type field value, with slash examples. It does not explicitly spell out when to prefer this over get_attachment_metadata or search_files, but the path-source context is clear enough for most selection decisions.

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