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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds value beyond that: it discloses the approximate result-set size (~200), the fields attached to each platform, and the alphabetical listing behavior. No pagination or edge-case behavior is discussed, but nothing is contradicted.

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 compact sentences, front-loaded with the identification of the resource, followed by the cross-tool linkage and an example. No repetition of schema fields, no filler.

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 burden of explaining returns, and it names the key attributes (abbreviation, hardware generation, platform family) plus scale. The full shape of a platform record (id, name, logo, etc.) is not enumerated, but an agent has enough to call and interpret it.

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 query (substring, omit to list alphabetically), limit (1-200, default 50), and _apiKey are all fully documented in the schema. The description's example reinforces the query format, and the note about ids feeding platform_id clarifies output semantics rather than this tool's own parameters. Baseline 3 is appropriate.

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 or search the ~200 gaming platforms IGDB tracks') and scopes it with the kinds of platforms included (consoles, handhelds, computers, arcade systems, digital storefronts). The scale (~200) and returned attributes make it clearly distinguishable from siblings like igdb_companies, igdb_game, and igdb_search_games.

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?

Explicitly ties this tool to the sibling that consumes its output: 'Its ids are what igdb_search_games({ platform_id }) filters on', and provides a concrete call example. Missing an explicit when-not-to-use (e.g., use igdb_game for a single known platform id), but the context is clear enough to route correctly.

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