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

Annotations already declare this as a read-only, idempotent, non-destructive closed-world operation, and the description still adds real value: the async lifecycle (pending/ready/failed with failure reason), the polling cadence, the cost, and the payload shape once ready. Fail-state behavior and timing are exactly what an agent cannot infer from the hints.

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?

Front-loaded with the verb and resource, then the lifecycle, then the polling instruction — good ordering with no filler sentences. The long parenthetical listing the analysis sections is dense but genuinely helps an agent judge whether the payload is worth fetching.

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 and no annotations covering returns, so the description must describe the response itself — and it does, including status values, failure reasons, and the full content set once ready. Polling guidance closes the remaining operational gap for a one-parameter async fetch.

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 coverage is 100% and the single parameter is already documented as 'Breakdown id from ad_breakdown.', which the description merely restates. Baseline 3 applies since the schema carries the parameter burden.

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 ('Read one Ad Breakdown') and explicitly ties the required id back to the sibling tool ad_breakdown, so an agent can separate this read/fetch step from the creation step. The enumeration of what becomes available once ready further pins down the tool's role.

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?

Gives concrete operational guidance: 'Free' and 'Poll every 20–30 s while pending,' which tells the agent exactly when and how to re-invoke. It stops short of naming when not to use it or pointing to an alternative (e.g., a list or batch variant), so it is clear context rather than a full when/when-not rule.

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