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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive. The description adds behavioral context: it explains the two modes and what is returned ('counts/values' vs 'metadata and all items inside'). This goes beyond the annotations and helps the agent predict the tool's output shape.

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 a single, well-structured sentence with two clear conditional clauses. It front-loads the main verb and resource, and there is zero wasted text. It is concise yet informative.

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 tool has 8 optional parameters and no output schema. The description covers the core behavior and return content for both modes. While it doesn't describe the exact response structure for items or collections, the schema and the phrase 'optional filters' provide sufficient context for an agent to invoke the tool correctly. It is complete enough for a read-only list/get operation.

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%, with each parameter explained in the schema (e.g., 'only when id is provided'). The description adds only a generic mention of 'optional filters,' which adds little meaning beyond the schema. Since the schema already carries the parameter semantics, a baseline of 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 clearly states the tool's dual purpose: 'List all collections OR get a specific collection with its items.' It uses specific verbs ('List', 'get') and identifies the resource ('collections'), making it distinct from sibling tools like get_item or search_saved. However, it doesn't explicitly contrast itself with siblings, so I deducted one point.

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 provides clear usage context: 'Without id: returns all collections... With id: returns that collection's metadata and all items inside.' This tells the agent when to omit or provide the id, and that filters apply only with id. It doesn't mention exclusions or alternatives explicitly, but the guidance is clear and practical.

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