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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent), so the bar is lower. The description adds one genuinely useful nugget beyond annotations — that the call does not consume credit — which aids cost-aware selection, but discloses nothing else about execution or scope.

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 terse sentences with purpose front-loaded and the credit caveat immediately after. The trailing 'Related:' line is of marginal value but does not bloat the definition.

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?

For a read-only, single-parameter tool with a full output schema and complete annotations, the description covers purpose and the credit constraint adequately. The only real gap is the absence of explicit routing to run_rank_check for a fresh check.

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 siteId is fully documented in the schema, so the baseline is 3. The description adds no parameter detail and never mentions siteId or the primary-site default.

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 (shows) and resource (tracked keyword positions) with clear temporal scope (now and over time), plus the 'winners and losers' framing. It distinguishes itself from research_keywords and run_rank_check implicitly, but never names a sibling, so it stops short of a 5.

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?

'Does not spend credit' implies this is the non-charging read path versus a spend-credit check like run_rank_check, but that alternative is never named. The 'Related:' list points at list_saved_keywords and save_keywords, which are related rather than decision-driving alternatives, leaving usage implied.

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