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 useful non-schema context: the catalog is the same registry the local @idosgames/mcp server serves, and it explicitly notes it takes no title_id, clarifying the call is global and unfiltered. It does not discuss pagination or catalog size limits, keeping it short of a 5.

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?

Front-loaded with purpose and the read-only/no-title_id constraint, and every clause carries information. The mid-sentence field enumeration is long and dense, which slightly hurts scannability, but each field it lists is load-bearing given there is no output schema.

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?

There is no output schema, and the description compensates by enumerating the returned fields (id, name, type, engine, genre, summary, provides, tags, preview media, demo url, inBase, uses, events) and explaining the non-obvious ones. Combined with the type semantics, an agent has everything needed to call it and interpret the result.

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?

Zero parameters, so the baseline is 4. The description reinforces this with 'takes no title_id', preventing an agent from attempting a title-scoped call, which is a small but real addition over the empty schema.

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 composable iDos Games game modules in the catalog') and immediately disambiguates it from sibling reads by noting the 'type' distinction (template = complete game to start FROM; feature = add-on system). An agent can separate this from get_module and search_modules without opening a schema.

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?

Gives an explicit when-and-what-next: 'Read \'provides\' to reuse a ready module instead of building the feature from scratch, then get_module to pull its source.' It names the follow-up alternative (get_module) and the condition that selects it, leaving little to inference.

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