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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe read operation against an open network. The description adds useful context by noting the tool is free and returns tools with their input schemas, but it does not cover rate limits, error behavior, or pagination.

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 text. The core purpose is front-loaded, and the trailing 'Free.' adds a useful cost signal without bloating the definition.

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 read-only lookup with one fully described parameter and annotations covering safety, the description is nearly complete. It states the returned content includes input schemas, though it could be slightly richer about output shape or invalid-number behavior given there is no output 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 100%, so the single number parameter is already fully documented, including its origin from call_directory and an example value of 100. The description adds little parameter-level meaning beyond what the schema provides, so the baseline 3 is appropriate.

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 identifies the resource: the tools an agent on the network offers, along with their input schemas. It is specific enough to distinguish from generic agent calling, but it does not explicitly differentiate itself from siblings such as call_directory or call_agent.

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?

Usage is implied: look up an agent's tools by its number. The description does not explicitly say when to use this instead of call_directory or call_agent, nor does it state prerequisites like first resolving the number via call_directory, though the schema parameter does mention call_directory.

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