Get one game

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: failure semantics (found=false, unresolved with ambiguous/no_match reasons) and the null-means-unknown-not-zero rule, which prevents misreading missing data. It says nothing about size limits, ordering, or whether all listed fields are always present.

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?

Tagged sections (use_case, important_notes, example) keep it front-loaded and scannable, with the critical resolution rule placed early. The field enumeration is the only padding, and even that is expressed as a compact comma list rather than prose.

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 an output schema present, the long enumeration of returned fields is partly redundant, and the description never needs to explain return shape. Everything an agent needs to call it correctly — input form, ambiguity recovery, null semantics, and a worked example — is present, so completeness is strong despite that redundancy.

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%, so the schema already documents the single 'game' parameter and its min/max length. The description still contributes meaning the schema lacks: the acceptance of a numeric app id or an exact name, the ambiguity fallback, and a concrete call example. Baseline 3 raised to 4 for that added resolution semantics.

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?

The description leads with 'Everything about one game' and enumerates the exact payload domains (playtime, Deck rating, ProtonDB, HLTB, triage lane, note, queue position, couch score, store link), so the resource and single-game scope are unmistakable. It never contrasts itself explicitly with the sibling backlog_find_games, which is the only thing keeping it from a 5.

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 important_notes give concrete operating guidance: pass an app id or exact name, and when the name is ambiguous or unmatched the call returns found=false with unresolved candidates plus a reason code, at which point the agent should pick by app id or ask the user. It stops short of stating when to reach for this versus backlog_find_games for discovery.

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