player_inventory

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

Goes far beyond the annotations: explains that type is not an exact row-type predicate, item_detail_id filters locally before the row/size bound, counts are reported, truncation is explicit with no continuation, and the call makes one logical GET with a 2-MiB transport bound. This adds substantial behavioral context without contradicting readOnlyHint, openWorldHint, or idempotentHint.

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?

The description is dense and front-loaded with the core purpose, and nearly every clause adds behavioral or routing value. The specific observation about item detail ID 322 being absent is narrow but informative; slightly more focus could make it tighter.

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?

Even without an output schema, the description covers request shape (one logical GET, transport bound), return behavior (counts, truncation, preservation of records/quantities/wire types), and domain limitations (staking eligibility, alternative power-core tools). An agent has enough context to select and call this tool correctly.

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 input schema has no descriptions, so the description carries the burden. It adds meaning for type as an upstream filter with caveats, item_detail_id as a local post-filter before limits, and username as the account selector. It does not enumerate valid type values, but the open-world caveat is explicitly stated.

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?

Opens with a specific action and resource: "Read one account's inventory with an explicit upstream type filter." It also distinguishes itself from related siblings by noting that separate land_power_core_available and land_power_core_grouped tools exist for dated populated STK-LND-PCR contracts, helping an agent identify what this tool is and is not.

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?

Provides concrete when-not guidance: inventory presence does not establish staking eligibility, and it explicitly names alternative tools for power-core contract data. It also sets expectations about local filtering, truncation, and no continuation, so an agent can decide whether this tool is sufficient before invoking it.

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