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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety is covered. The description adds valuable context that annotations cannot carry: exactly what data comes back and that a word page with native-audio examples is included. It does not cover behavior for unknown words or missing data, keeping it short of 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?

A single dense sentence that front-loads the core question ('how often is a word heard') and then enumerates the metrics. No filler, though the enumerated metric list makes it run long within one sentence.

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 only two required params, no nested objects, and no output schema, the description carries the return-value burden and does so by listing the metrics and the linked word page. Nothing critical is missing for correct invocation, though expected behavior for a word absent from the corpus is unstated.

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 both parameters are documented in the schema (word forms for Japanese/English, language enum). The description's mention of 'Japanese or English word' and 'heard' only echoes the enum and hints at spoken-corpus matching; it adds no syntax or format detail beyond the schema. 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?

Names a specific resource and scope: word frequency (number of videos, occurrences, coverage, rank, level) across LingoDew's video corpus. It is clearly distinguishable from siblings like channel_stats and find_videos. It is phrased as a noun description rather than a verb, but the intent is unambiguous.

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?

No explicit when-to-use statement, no exclusions, and no mention of sibling tools. Usage is only implied by the described output (a vocabulary/corpus statistics lookup), so an agent must infer the trigger conditions itself.

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