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

Annotations already cover the safety profile (read-only, idempotent, non-destructive, closed domain), and the description goes well beyond them: it discloses the three separate inclusion triggers (two member installs agreeing on a boss, an officer-published board, or a character sighting), hidden-guild suppression, and the crucial 'unrecorded, not zero' semantics when player pages are disconnected. That last point materially changes how an agent should interpret results and is not inferable from annotations or schema.

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?

Content is front-loaded: purpose and return fields come first, then inclusion rules, then the routing instruction. It is dense but nearly every clause carries operational meaning; the sentence about reading Everloot's public data and explicit missing-data reporting is somewhat repetitive with the adjacent 'unrecorded, not zero' sentence.

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?

An output schema exists, so return values need not be formally specified, yet the description still orients the agent to the notable fields and their caveats. For a two-parameter, read-only lookup it covers matching semantics, coverage conditions, exclusions, and result interpretation, leaving nothing an agent would need before calling 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 both parameters are already documented, yet the description adds the constraint that the query matches guild names only and never member names, which prevents a common misuse. The 'starts with what you typed' phrasing reinforces prefix rather than substring matching, though it does not add limits or defaults beyond the schema.

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 opening sentence names a specific verb (finds) and resource (guilds) with precise matching semantics: prefix match on guild name. It also enumerates what comes back (realm, faction, observed character count, agreed boss-kill count and date), which no sibling tool does. An agent can distinguish it from guild_board and guild_rankings without opening either 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?

It gives an explicit routing rule: use this to resolve a guild's exact name and realm before calling guild_board, and use guild_rankings for a ladder. It also states a hard exclusion (hidden guilds are omitted), which is the kind of when-not guidance most definitions omit.

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