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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description adds valuable behavioral context: the tool does not render UI, returns the same payload as list_jobs, is polled every ~5s while rows are in flight, and caps task_tokens at 20. No contradiction with 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 compact and well-structured, front-loading the most critical instruction ('Do not call this from the agent') and then providing necessary context in a few tight sentences. No filler or repetition.

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?

Given the output schema, annotations, and sibling context, the description covers everything an agent needs: purpose, non-usage, alternative, payload equivalence, polling behavior, and parameter constraints. The only minor ambiguity is exact handling of more than 20 tokens, but this is negligible here.

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 must compensate, and it does: task_tokens are 'job IDs to poll, most recent first' and 'Capped at 20.' This adds meaningful semantics beyond the bare array-of-strings schema, though it stops short of specifying exact ID formats or behavior when the cap is exceeded.

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: 'Poll job rows for the jobs card.' It also explicitly differentiates itself from list_jobs by noting the same payload but no widget rendering, so an agent can distinguish it from siblings without inspecting schemas.

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 is explicit about when not to use it ('Do not call this from the agent') and names the correct alternative ('Agents must call list_jobs to show or refresh the card'). It also explains the intended caller and cadence, leaving no ambiguity about usage.

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