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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile needs no restating. The description adds value beyond them: XP sources (reviews, vouches, invitations), the fact it is free with no payment or key and matches the public Ethos API, and a sample scalar output. Missing only things like rate limits or caching/staleness behavior.

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?

Front-loaded with the practical question the tool answers, then scope, then the pairing advice and a compact input/output example. The opening rhetorical question and the 'long-standing vs fresh or dormant' clause are slightly padded, but no sentence is wasted overall.

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 tool with no output schema, the description covers what is returned (a total XP number, shown by example), the data source, the cost, and the natural companion metric. There is no output schema to defer to, and the example output fills that gap adequately.

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 enumerates every accepted userkey form (address, profileId, service:x.com, Discord, Telegram), so the description largely echoes it. The concrete example input {"userkey":"profileId:1"} adds a small amount of usable guidance but nothing about resolution ambiguity or invalid-key behavior.

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 and resource: "Total XP earned across all seasons for a userkey," and immediately frames it as a history/activity measure as opposed to the credibility score, which lets an agent separate it from ethos_score and the user-lookup siblings without opening a schema.

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?

Gives clear when-to-use framing ("How active and invested is this person..." and "Use it alongside the credibility score to weigh how much history stands behind a reputation"), which routes the agent toward pairing it with ethos_score. It stops short of naming explicit exclusions or saying which sibling to call for the lookup portion instead.

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