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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the genuinely new behavioral fact that a free Messe Atlas account is required and a sign-in prompt may appear — useful auth context an annotation cannot express.

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 with no padding and no repetition of the title. The auth prerequisite leads and the payload description follows, which is a reasonable ordering though slightly less front-loaded on 'what it does' than ideal.

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 one-parameter read with no output schema, the description compensates by summarizing the return shape (organizer description, parent company, top event series) and the auth requirement. With annotations covering safety and the schema covering the identifier, an agent has enough to call it correctly.

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 parameter already documents 'Slug or uuid, as returned by the search tools.' The description's 'by slug or uuid' repeats the schema rather than adding format, casing, or lookup guidance, so the baseline 3 applies.

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 ('One organizer by slug or uuid') and names the fields the single result carries (description, parent company, top event series), which separates it from list/search siblings like search_organizers. It stops short of explicitly contrasting itself with the other get_* tools, but the resource noun does the disambiguating work.

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?

Usage is implied — fetch one organizer by identifier — and the account/sign-in prerequisite is stated. There is no explicit when-to-use guidance, no mention that search_organizers is the way to obtain the slug/uuid for this call, and no exclusion of alternatives.

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