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

Annotations already establish that this is a read-only, closed-world, non-destructive operation. The description adds a useful access constraint with 'Premium' and clarifies that results are aggregate rather than per-card, but it does not describe response shape, pagination, or rate limits.

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 very short and front-loads the key output: invested vs market P&L aggregates. The fragments are efficient, though the terse 'Premium:' label could be clearer.

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 read-only analysis tool, the description is still incomplete: it explains the aggregate output but says nothing about the game and language filters, and there is no output schema to fill that gap. The access-tier note helps, but the parameter behavior remains undocumented.

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 schema has two parameters, game and language, with 0% description coverage, and the tool description does not mention either parameter. It provides no allowed values, default behavior, or filtering semantics, leaving the agent to guess their meaning.

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 analytical output: invested vs market P&L aggregates for the user's collection. It also distinguishes the tool from per-card dumps and listing tools, though it does not name the closest sibling such as collection_summary.

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 phrase 'No per-card dump, no listings' implies when not to use this tool, but it does not explicitly name alternatives or explain when to choose collection_summary or collection_search instead. Usage is inferable but not fully guided.

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