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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds genuine value by confirming there is no input and that no squad, club, or account data is touched. That data-scope statement is useful extra assurance beyond the structured fields, though it does not discuss result size or caching.

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?

Three short sentences, front-loaded with purpose and followed by the ID-disambiguation and the no-input/no-data note. Every sentence carries distinct information with no redundancy.

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 parameterless read-only catalog with an output schema, an agent needs only to know what is listed, what the IDs mean, and that nothing private is accessed — all present. Return values are already covered by the output schema, so nothing material 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, which sets the baseline at 4. The description reinforces this with "Takes no input," leaving no ambiguity for the caller, but there is no additional parameter meaning to add.

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 ("List the native FC27 campaign-squad catalog") and immediately clarifies the payload: source IDs, names, and dates. It also pre-empts confusion with the similarly named squad tools by saying no squad, club, or account data is read, and explicitly separates these IDs from rarity EA IDs.

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 "for player inclusion/exclusion filters" makes the intended use clear: fetch this to obtain filter keys before querying players. It stops short of naming a specific sibling (e.g., the player listing tool) or stating when not to use it, so it is clear context rather than explicit routing.

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