capabilities

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

The annotations already declare readOnlyHint=true, openWorldHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context by stating that no key, filesystem access, network request, or processing allowance is required, which goes beyond the annotations.

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 two short sentences with no wasted wording. The purpose is front-loaded, and the operational caveat follows naturally.

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 zero-parameter informational tool with rich read-only annotations and no output schema, the description is largely complete. It says what will be described and what is not required, though it could clarify the return format or how subscription links are presented.

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?

This tool has zero parameters, so there are no parameter semantics to explain. The baseline for a zero-parameter tool is 4, and the description introduces no parameter confusion.

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 states a specific verb, 'Describe', and concrete resources: four supported file tools, limitations, and subscription links. It clearly marks this as an informational capability tool rather than one of the sibling file-operation tools, though it does not name the four tools 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?

The description does not say when to call this tool versus the sibling file tools, nor does it give exclusions or alternatives. The note about not requiring a key, filesystem access, network request, or processing allowance is prerequisite information rather than usage routing.

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