pl_call

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

Annotations already include readOnlyHint, idempotentHint, and destructiveHint=false. The description adds meaningful context: parameters are passed verbatim, validation happens at the aggregator before forwarding, and specific error codes are enumerated. This enriches the behavioral model without contradicting 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 well-structured: a concise opening, practical examples, parameter details, and a list of errors. Slightly long for an escape hatch but every sentence contributes necessary information.

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 generic escape-hatch tool, the description is highly complete. It covers use cases, parameter semantics, how to discover native names, validation behavior, and error handling. The output schema is present, so return-value details are not needed.

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 0%, so the description compensates well. It explains the 'arguments'/'args' alias and clarifies that either can be used (not both), and that keys must be native parameter names, directing to pl_list_sources for discovering them. Source and tool are self-explanatory given the context.

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 states the tool's function: 'call any native tool of any registered source.' It distinguishes itself from sibling unified tools by positioning as an 'escape hatch' for operations not covered, with concrete examples (citator, DPA statistics, etc.).

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?

Explicitly tells when to use the tool: 'For operations the unified tools do not cover.' It also provides alternatives for finding native parameter names (pl_list_sources) and lists possible error cases, fully guiding the agent.

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