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

Annotations already declare readOnly/openWorld/non-destructive, yet the description genuinely adds execution and provenance context: one fixed Live task with no follow-up requests, estimates are not Google Ads metrics, and completed results persist in call history. However, statements like 'Prices remain unapproved' and 'source-freshness rules' are cryptic enough that an agent cannot act on them.

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?

Five short sentences with no padding, but they are front-loaded with caveats rather than purpose, and several ('Prices remain unapproved') read as boilerplate that costs the reader without informing the call.

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 two-parameter read-only estimate tool with no output schema, the description should say what the estimate payload contains (volume figure, missing-evidence markers) and in what units. It gestures at 'explicit missing evidence' but never describes the return, leaving the agent to infer the shape of 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 0% aside from the item constraint string, so the description carries the burden and mostly fails. The only parameter-relevant note is 'no language filter', which hints that keywords should not be language-qualified, but nothing is said about the fixed 'US' market or the 20-keyword cap.

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?

The description opens with the noun phrase 'clickstream estimate' without a verb or a statement of what is actually returned (estimated search volume for the supplied keywords). The title supplies that meaning, not the description, and nothing distinguishes it from close siblings such as nexscope_seo_keyword_metrics, nexscope_seo_ai_keyword_volume or nexscope_seo_search_volume_country_distribution.

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 when-to-use guidance and no named alternative anywhere in the text. The closest thing to guidance, 'Seven-day source-freshness rules apply only to dependent requests', presupposes concepts ('dependent requests') the agent has no way to resolve.

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