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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the added 'Read-only, no side effects' line is partly redundant. What is genuinely additive is the disclosure that install_url is null for coming_soon add-ons and that the `say` field is a ready-to-relay sentence, which tells the agent how to behave on edge cases rather than just what data comes back.

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 sentences that are front-loaded with the payload (what is returned) before the edge-case handling and the read-only reassurance. Dense with information and free of filler, though the closing 'Read-only, no side effects' repeats the annotations.

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 no output schema, the description carries the return-value burden and does so by enumerating the returned fields and explaining the two special ones (`say`, null install_url). For a zero-parameter, read-only lookup with annotations covering safety, nothing needed to invoke or relay 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?

The tool takes zero parameters, so the schema has nothing to document and the baseline of 4 applies. The description correctly says nothing about inputs instead of padding with irrelevant argument talk.

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 states exactly what is returned: Chrome add-ons for Connections Email, Schedule and Notes, with per-add-on name, browser, status, install_url, summary and highlights. That distinguishes it cleanly from the many sibling tools (email_get, calendar_list, etc.). It is descriptive rather than verb-led, but the resource and scope are 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?

It establishes the context of use ('What Connections offers outside this chat') and gives a concrete conditional handling rule for install_url being null (status coming_soon) plus a 'never invent a store link' guardrail. It does not name sibling alternatives or explicit when-not-to-call conditions, so it falls short of a 5.

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