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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real behavioral context beyond them: the return can be either a tool list or a UI page, and it imposes a privacy constraint ('do not include personal details'). It does not say what happens when no capability matches, which keeps it from 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?

Three short sentences, each earning its place: purpose/return, when-to-use with examples, and input constraint. The fallback condition is front-loaded where an agent will see it.

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 single-parameter, read-only lookup with no output schema, the description supplies everything needed: the routing condition, the two shapes of the response, and the input phrasing rules. Nothing an agent needs to call it correctly 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 coverage is 100% and the schema already supplies examples for 'goal', so the baseline is 3. The description adds genuine guidance not in the schema: keep the task to a few words and omit personal details, which shapes how the single parameter should be written.

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 names a specific verb and resource ('Check whether TrendsAGI can do a task') and states the two possible outcomes: a set of tools or the app page where the user does it. It is clearly distinguishable from the sibling tools, which are all concrete data-retrieval calls rather than a capability lookup.

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?

It gives an explicit routing rule — 'Use when no other tool fits the user's request' — and concrete examples (setting up an alert, exporting data, connecting an ad account). It also instructs how to phrase the input ('a few words'), so both when-to-use and how-to-call are covered.

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