users_get_by_short_uuid

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds nothing beyond that, however: it does not say whether a missing short UUID returns an error or null, and it is not a mutation tool so there is little to disclose. With annotations carrying the load, a 3 is the correct baseline.

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 short sentence, front-loaded with the verb and resource and free of filler. It is appropriately sized for a trivial lookup, though the terse phrasing borders on under-specification rather than true economy.

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 lookup surrounded by several near-duplicate siblings, the description does not explain which identifier this tool consumes, how it differs from users_get or users_get_by_username, or what happens when the short UUID is unknown. With no output schema and no parameter documentation, an agent lacks the information needed to confidently route to this tool.

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 0% and the description adds no semantics for the single shortUuid parameter, so it does not compensate for the missing documentation. On the other hand, the parameter name is self-describing and there is only one required param, keeping the practical risk low. Baseline 3 is defensible here.

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 verb and resource (get user by Short UUID), which is clear on its face, but it does not differentiate itself from the many sibling lookups: users_get, users_get_by_username, users_resolve, metadata_user_get, or the subscription-side subscriptions_get_by_short_uuid. The reader cannot tell which identifier scheme selects this tool over its near-identical siblings.

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?

No guidance on when to use this lookup versus users_get, users_get_by_username, users_resolve, or users_stream. The only distinguishing signal, that it keys off a short UUID rather than a numeric id or username, is left implicit in the name.

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