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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing the asynchronous scan lifecycle (this reads the result of a previously started scan). However it omits behavior on a not-yet-finished or expired scan, and any polling/rate guidance.

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, zero waste, with the routing condition front-loaded before the parameter note. Every clause earns its place.

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?

An output schema exists, so return values need not be explained, and the description covers the trigger and the parameter's identity requirement. The remaining gap is error/edge-case behavior (scan not found, not finished, expired), which an agent would need for robust polling.

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 schema description already says the URL is 'used for find_newsletter_sponsors'. The description's 'takes the same newsletter web address' reinforces identity matching between the two calls, but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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+resource ('read the result of a sponsor scan') and explicitly anchors it to the sibling that creates that state, find_newsletter_sponsors. An agent can distinguish this polling tool from the initiating tool and the other sibling rate/brand tools without opening any schema.

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 a concrete trigger condition: use it when find_newsletter_sponsors reported the scan was still running. The alternative (the initiating tool) is named, though there is no explicit guidance on when NOT to call it (e.g. completed/expired scans) or how often to poll.

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