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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds genuine context beyond that — that the data is 'live' and includes 'presence' aggregated across Claude, Codex, and Git — but says nothing about freshness windows, what happens for an unknown handle, or auth requirements for Git sources.

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 well-formed sentence with the distinctive information (live, multi-source, any account) front-loaded and no filler. It is arguably too terse given how much it leaves unspecified, but nothing in it is redundant.

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 one required parameter, no output schema, and full annotation coverage, the description does not need to explain return values. Still, for a tool that aggregates three distinct activity sources plus presence, a sentence on what the response contains or how 'live' is bounded would materially help an agent decide when to call it.

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%, so a 3 is the baseline; however, the schema's only description is the word 'Handle', which conveys no format. The description's phrase 'for any account' adds slight meaning by implying the handle identifies an arbitrary account rather than the caller, but it does not specify handle syntax such as '@user' or an ID.

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 the resource and its data sources precisely — 'Live Claude/Codex/Git activity and presence for any account' — which is far more specific than the bare title 'Account activity'. The scope qualifier 'for any account' hints at the distinction from the sibling 'activity' tool, though it never states that contrast outright.

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?

There is no explicit when-to-use statement, no mention of prerequisites, and no named alternative such as 'activity', 'whoami', or 'find_agents'. The only implicit cue is 'for any account', which suggests an arbitrary-account lookup rather than self-scoped, but the agent must infer that.

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