list_activities

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so "Read-only" is largely a restatement. The genuinely additive piece is that the response carries activity codes intended as input to other tools, but it says nothing about whether the list is exhaustive or how the codes are formatted.

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 front-loaded sentence with no filler, and the key detail (returns codes for other tools) is not buried. The parenthetical example list is slightly long and contains a typo ("randonné"), which keeps it off a 5.

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 zero-parameter, no-output-schema lookup tool, the description covers purpose, output intent and safety adequately. Minor gaps remain around whether the list is static or configurable per club, but nothing essential to making the call is missing.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline of 4 applies. The description correctly does not invent parameters.

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?

Specific verb and resource ("List the club's activities") plus the domain term the club uses ("commissions") and a concrete example set. It also states the payload the caller gets back — the code to pass as `activity` — which separates it cleanly from sibling list tools like list_sorties and list_formations.

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 phrase "with the code to pass as `activity` to the other tools" gives an explicit call-this-first context, which is the real reason an agent would invoke it. It stops short of naming a specific alternative or stating when not to call it, so it lands below the top tier.

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