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

Annotations already declare it is non-read-only, open-world, non-idempotent, and non-destructive. The description adds important context beyond that: it spends one autocomplete request per prefix and one keyword inspection per inspected term from monthly allowances, and returns the refreshed gap. It doesn't detail side effects on stored data, but the quota-cost disclosure is valuable.

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 tightly packed sentences, front-loaded with the action and mechanism. Every sentence earns its place by explaining process and quota impact without waste.

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 three-parameter tool with full schema coverage and no output schema, the description gives a complete picture of how it works and what it returns ('refreshed gap'). It could be slightly richer about what the refreshed gap contains, but nothing critical for correct invocation is missing.

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%, so defaults and limits are already documented. The description reinforces the prefix-default behavior ('words from the competitor's title') and ties inspected terms to cost, but adds no syntax or format details beyond 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?

Names a specific action (widen a competitor's keyword gap) and describes the exact mechanism: store autocomplete plus keyword inspection. An agent can distinguish this from siblings like get_keyword_gap (read-only view) or run_autocomplete (single lookup) without opening the 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?

States the tool's context clearly: expanding a competitor's gap using title words or provided prefixes. However, it does not explicitly say when not to use it or name alternatives like get_keyword_gap for simply viewing the current gap.

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