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

Annotations already declare readOnlyHint=true, and the description adds no contradictory behavior. It adds useful context about the returned information (drop rates, NPC prices, quest rewards) without needing to restate the read-only nature. It does not cover rate limits or auth, but the simple read-only profile makes this adequate.

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?

Two sentences with zero filler: the first front-loads the core purpose and resource scope, the second gives the usage preference. Every word earns its place.

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?

For a simple two-parameter tool with an output schema and read-only annotations, the description covers what it does and when to use it. The only minor gap is not explicitly explaining when include_inactive should be true, but the schema already documents it, so no critical information is missing.

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%, with both item_name and include_inactive described in the input schema. The description adds the single-item aggregation context but does not elaborate parameter behavior, so the 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?

The description states a specific resource ('one item') and action ('Every in-game source ... in a single call'), enumerating creature drops, NPC sales, and quest rewards. This clearly differentiates it from siblings like tibia_find_items and tibia_find_creatures by emphasizing aggregation across source types.

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?

It gives explicit guidance: 'Prefer this over three separate lookups,' which tells the agent when to choose this tool instead of performing multiple queries. It does not name the specific alternatives or exclusion conditions, but the context is clear enough for selection.

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