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

Annotations declare readOnlyHint=false and openWorldHint=true, and the description adds the key behavioral detail explaining why it isn't a pure read: it consumes an inspection quota, except for already-tracked keywords. That quota rule is genuine context beyond the annotations. It does not cover latency, caching, or error behavior, so not a 5.

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 purpose, followed by a dense but useful enumeration of return fields and the quota rule. Every clause carries information, though the long return-value list is list-heavy; it earns its place only because no output schema exists.

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 carries the burden of describing returns and does so thoroughly (difficulty_score, traffic_score, KEI with level, top-20 ranking apps with fields, related suggestions, tracked status). Combined with the quota behavior and full parameter documentation, an agent has everything needed to call it correctly.

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 the lang parameter in particular is richly documented (market vs. language-region distinction). The description adds no parameter-level meaning beyond the schema, so the 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 and resource ('Deep-analyze any keyword') with an explicit scope qualifier ('even ones you don't track'), so the agent knows this works on untracked keywords. It does not name any sibling (e.g. list_keyword_inspections or run_niche_analysis) to differentiate, 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?

Usage is implied by the scope note ('any keyword, even ones you don't track') and the quota caveat, which tells the agent the operation is worth running on tracked keywords. However, there is no explicit when-to-use/when-not guidance or reference to alternative tools like run_autocomplete or run_niche_analysis, leaving the routing decision to inference.

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