call_tool

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

Annotations already declare destructive, non-read-only, non-idempotent, and open-world behavior, but the description adds substantial context: the invoked tool runs with the same validation, guards, readback, effects, and destructive capacity as a direct call. It also lists refusal conditions, renamed-tool behavior, and that the reply is passed through unchanged.

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 definition is front-loaded with the core purpose and example, followed by routing guidance, behavioral caveats, refusal cases, and return semantics. Every sentence adds operational value for safe invocation of an arbitrary meta-tool.

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 complex arbitrary-dispatch tool with no output schema, the description is complete enough to call correctly: it explains discovery flow, argument structure, validation behavior, refusal modes, destructive potential, rename handling, and that the named tool's own reply is returned unchanged.

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?

Although schema coverage is already 100%, the description adds meaningful parameter semantics beyond the schema: a concrete example, acceptance of a JSON string for `arguments`, unknown-name errors with closest matches, and the fact that an old name of a renamed tool will run the new tool with an explanatory reply.

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 and resource: it runs any server tool by name, with `name` identifying the tool and `arguments` carrying that tool's parameters. It clearly distinguishes itself from siblings by saying to use it only for tools not in the tool list, after `find_tools`, and to call listed tools directly.

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 explicitly gives the when-to-use condition (a tool not in the tool list), the prerequisite discovery flow (`find_tools`, then `describe_tool` when parameters are unclear), and the alternative (call a listed tool directly). No relevant routing decision is left implicit.

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