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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered; the description goes further by disclosing the four possible status outcomes (live/dead/pending/unknown) and that dead invites still resolve to a server, which is non-obvious behavior. It does not mention rate limits or how stale the 'last saw' data can be.

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?

Single dense sentence that front-loads the action and the input formats before the return semantics. It is somewhat clause-heavy with three comma-stacked ideas, but no sentence is wasted.

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 burden of explaining returns and does so by naming all four status values and the associated server data. Minor gap: nothing about invalid/unknown-format input handling or response shape.

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 single param is already documented, so the baseline is 3; the description adds concrete accepted syntax (discord.gg/abc, discord.com/invite/abc, bare code) that meaningfully clarifies what strings are valid. No error behavior for malformed codes is described.

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 ('look up a Discord invite link or code') and enumerates the three accepted input forms, which immediately distinguishes it from get_server/search_servers lookups. An agent can tell this checks a known invite rather than discovering servers.

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 description implies usage by spelling out accepted input formats and what the result means, but it never states when to prefer this over get_server or search_servers, nor any exclusion case. The when-to-use signal is left to be inferred from the sibling names.

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