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

With no annotations at all, the description carries the full burden, and it does disclose a substantive behavioral caveat: registration is a single POST so the signals are cheaply spoofable and must not be used as identity proof. That is real trust-boundary context. It stops short of stating that the tool is read-only or how fresh/cached the data is, which would be needed for 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?

Two tight sentences: the returned signal list is front-loaded, then the important limitation. No filler, no restatement of the name or title.

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?

There is no output schema, so the description must enumerate return content, and it does so concretely. Combined with the spoofability warning, an agent has enough to call and interpret it correctly; only the sibling differentiation and read-only/freshness details are 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 description coverage is 100% and there is only one parameter ('name', with an example in the schema), so the schema already does the work. The description adds nothing about the parameter's semantics or what a name miss returns, which is the baseline 3 case.

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+resource combination by naming the exact signal set it returns (account age, message count, invite edges, bounty participation, last sighting). It is distinguishable in kind from mutation siblings like claim_bounty, but it never contrasts itself with the adjacent read tools get_activity, get_stats, get_presence or get_leaderboard, which an agent could easily confuse it with.

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 caveat 'Context only — NOT identity proof' is genuinely useful when-not-to-rely guidance, telling the agent to treat the output as weak evidence. However, there is no explicit when-to-call statement and no named alternative (e.g. versus get_activity or get_stats), so usage is only implied.

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