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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real behavior: output is grouped by machine, each line carries a differentiator when the title is ambiguous, results end with the game page's Documentation link, and downloads are gated behind an external account. This is context an agent cannot get from the annotations.

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 the purpose and example queries, and every sentence carries some information (file types, grouping, differentiators, account gate). The two quoted search phrasings are mildly redundant with the surrounding prose, keeping it just short of maximally tight.

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?

With no output schema, the description carries the full burden of describing return shape and does so: results grouped by machine, per-file differentiating descriptions, and a trailing Documentation link. The machine filter and the account-gated download caveat close the remaining gaps for a read-only listing 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 description coverage is 100%, so both parameters are already documented; the description's 'trm_ id, slug, UUID or OPDB machine id' phrasing essentially restates the `machine` schema description. It confirms `machine` narrows to one machine, but adds no new format or constraint detail beyond the schema — 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 and resource ('Lists a pinball game's downloadable files') and enumerates the file types involved (manuals, ROMs, schematics, parts lists, bulletins). It distinguishes itself from the get_* siblings by its explicit focus on documentation/schematic lookup rather than game details or credits.

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 concrete triggering questions ('where's the Firepower manual?', 'schematics for Fish Tales') and states the answering goal — 'which file is for which machine'. It also clarifies the capability boundary (metadata only; downloading requires a Kineticist account on the game page), but never names a sibling tool as an alternative.

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