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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds ordering (newest first), a hard result cap (up to 20), the returned field set, and a cost signal ('Free'), which are genuinely useful traits not present in the structured fields.

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 tight sentences with the scope, ordering and cap front-loaded, followed by the routing hint and cost note. Every sentence carries information an agent needs; nothing is padded.

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?

With no output schema, the description compensates by enumerating the returned fields (id, pass, status, run time, topic/keyword counts, current marker) and the ordering. Combined with the safety annotations, an agent has everything needed to call it correctly and interpret the result.

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 100% and both parameters are fully documented there, so baseline 3 applies. The description's 'up to 20' restates the limit's schema-declared default/max rather than adding syntax or formatting meaning, so it does not exceed the schema.

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?

Specific verb (Lists) plus a precise resource (keyword research runs for the site), and it names the sibling tool to use for a single run (get_research_run). An agent can distinguish it from get_research_run, get_research_status and run_keyword_research 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?

It routes the agent to get_research_run for a single record and signals cost with 'Free', giving clear context for when to call this versus the single-run reader. It stops short of explicit when-not conditions (e.g. what to do when there are no runs or when a fresh run is needed).

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