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

No annotations are provided, so the description carries the full burden. It discloses that it's a synchronous batch create, requires an idempotency key, and correlates by client_ref, which is useful. However, it doesn't mention potential failure modes (e.g., partial success, error handling) or the output format, which for a batch operation with an output schema might be important.

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, information-dense sentence with no fluff. It front-loads the core action and limit, then covers correlation and idempotency. 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?

Given the complexity of a batch operation, the description covers the main usage (batch, limit, correlation, idempotency). The output schema exists, so return values are covered by that. However, it lacks explicit error handling and partial-failure semantics, which would be valuable for batch calls. It's almost complete but has a minor gap in failure transparency.

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 50%, with the 'items' and 'idempotency_key' fields having descriptions, but the nested item properties like 'title' and 'locale' lack descriptions. The description adds context about 'client_ref' correlation and the idempotency requirement, which aids understanding. However, it doesn't compensate for the undefined 'locale' field and other nested parameters, so it's adequate but not complete.

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 clear action ('Sync batch create ≤100 links') and references the HTTP endpoint, distinguishing it from the singular 'shorten_url' sibling. However, it does not explicitly name the sibling or contrast the batch vs single behavior, so it's clear but not fully differentiated.

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 explicitly mentions 'batch' and the ≤100 limit, implying when to prefer this over the singular 'shorten_url' sibling, and mentions the correlation by 'client_ref', which is key for batch handling. However, it does not explicitly state 'use this instead of shorten_url for multiple links', leaving some inference.

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