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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context: the operation is asynchronous and results may not be ready, so the agent must poll rather than expect an immediate value. It says nothing about return shape or error states for an unknown/expired callId, which keeps it short of a 5.

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?

Two sentences, front-loaded with the action and followed by the operational instruction. No filler.

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?

There is no output schema, so the description is the only place a return-value shape could be explained, and it does not describe what a completed result looks like or what a not-yet-ready response returns. For a simple single-param read tool this is adequate but leaves a clear gap for polling logic.

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?

One required parameter with 100% schema coverage; the schema already documents callId as the ID returned from pcc_relay_tool_call. The description adds no format, lifecycle, or expiry semantics for the ID, so this is the baseline 3.

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?

States a specific verb and resource: retrieves the result of a previously relayed tool call, which cleanly distinguishes it as the retrieval counterpart to pcc_relay_tool_call. It doesn't explicitly name which relay sibling it pairs with in the description body, but the pairing is unambiguous from context.

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?

"Poll this endpoint until the executor has processed the call and posted results" gives a concrete usage pattern for an async workflow, telling the agent this is a post-relay retrieval step. It stops short of stating when not to use it, e.g. that a call that was never relayed has no result.

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