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

With annotations only providing false flags, the description carries the burden of disclosing side effects. It does so effectively by stating that duplicate names are rejected and that an unlocked draw is regenerated automatically. These are important behavioral traits that go beyond the schema and annotations, giving the agent a clear picture of the tool's impact.

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 three sentences and front-loads the core purpose. Every sentence adds value: purpose, preparation guidance, and side effects. No filler or redundancy.

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?

The description covers purpose, usage guidelines, alternatives, and key side effects. With an output schema present and parameter schemas for most fields, no critical context is missing. The tool's behavior is fully captured for an agent to invoke it 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?

Schema description coverage is 67%, and the players array itself lacks a schema description. The description compensates by implying that the players parameter must contain structured entries, not raw text, and warns against inventing placeholder names, adding meaning beyond the input schema. Fields like level and gender are well-covered by schema, so the description complements rather than repeats.

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 opens with 'Add players to the roster in bulk', a specific verb and resource that clearly states the tool's function. The bulk aspect distinguishes it from siblings like update_player, replace_player, and signup mode, making the purpose unmistakable.

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 description gives explicit usage guidance: it instructs to parse pasted lists or spreadsheets yourself and send structured entries, and explicitly says to use signup mode when names aren't known yet, providing a clear alternative. This tells the agent exactly when and how to use the tool versus other workflows.

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