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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds the useful scoping detail that only the related-topics widget is returned (not the full Explore payload), but says nothing about auth, rate limits, or whether keywords alone are enough to drive the call.

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 sentence with the scoping constraint front-loaded; nothing extraneous and the key differentiator appears immediately.

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?

An output schema exists, so return-value detail is not needed, and annotations cover safety. However, for a widget-extraction tool the description never clarifies its relationship to google_trends_explore or whether keywords must match a prior explore call, leaving a genuine workflow gap.

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% across all 8 parameters, so the schema fully documents hl, tz, geo, type, category, keywords, property, and time_range. The description adds no parameter meaning beyond that, which is the correct baseline when the schema does the work.

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 ("Returns") and resource ("related topics widget from the Google Trends Explore flow"), which distinguishes it from sibling widgets like interest_over_time or top_queries. It doesn't name those siblings explicitly, so differentiation is by implication rather than direct routing.

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?

The phrase "from the Google Trends Explore flow" implies this is a scoped extraction of one widget, but it never states when to use this versus google_trends_explore or the other explore_* tools, nor whether a prior explore call is required.

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